Tony Tony Chopper/History

No Disease is Incurable
Chopper was originally a reindeer with the slight oddity of a blue nose, which caused other reindeer to treat him as an outcast (always making him follow the herd from far back). However, when the young reindeer ate the Hito Hito no Mi, he was even more ostracized from his herd (and with the increase in intelligence granted by the fruit, now acutely aware of it) and struck out on his own. Unfortunately for Chopper, his attempts at communicating with the humans on Drum Island proved disastrous, he was shot by villagers who mistook him for the Abominable Snowman.

Luckily, though, he was rescued by the quack Dr. Hiluluk, who named him and took him in as his friend and "assistant". Although his deeds were of dubious medical value, Dr. Hiluluk became Chopper's role-model. Hiluluk taught Chopper his philosophy on life (that all diseases could be cured) and his strong faith in the Jolly Roger as a symbol of strength against all odds. The two went from house to house, administering their "cures" in a country where all doctors not sanctioned by King Wapol were banned.

When Hiluluk's health took a turn for the worse, Chopper found himself left out in the cold once again as the old man did not want Chopper to watch him die. But once Chopper found out what was going on, he was determined to find something to cure his mentor, his one and only friend. He soon found what he was looking for: a special kind of mushroom with skull-and-crossbones prominently displayed in the medical book, unaware of what that sign meant medically due to Hiluluk's praising of pirates and the jolly roger. Remembering what he overheard by some villagers that a "certain" type of mushroom can heal every illness, Chopper steals Hiluluk's favorite medical book to find the miracle mushroom. Chopper's arduous journey was a success, even though he risked his life and suffered many injuries, such as a broken left horn.

Hiluluk overwhelmed with tears of gratitude, ate the mushroom to show his love and appreciation to Chopper, (despite knowing that it would end his life) but Chopper would later find out from Dr. Kureha that he had given Dr. Hiluluk a fatal dose of poison. But Hiluluk was not to live much longer anyway. Declaring that he had a wonderful life (in the 4kids dub he declares he is a doctor)and after thanking Chopper, he committed suicide by blowing himself up outside of Drum Castle (before being killed by the poison, for Chopper's sake). Chopper, who had arrived to try and save him, was so upset over Hiluluk's death that and so angry that Wapol was making fun of it that then tried to attack him. Dalton, who had heard Hiluluk's last words and realised that the monster he called his son was trying to attack Wapol he then stopped him. He then, with tears in his eyes told him that he apologized for those who mocked Hiluluk death but that he could not beat Wapol if he could not beat him.

As for Hiluluk's last wish, Dr. Kureha (the last remaining doctor not owned by King Wapol) took Chopper in and taught him "real" medicine for the next 6 years. Chopper worked as hard as he could, in order to become a doctor like his idol, Hiluluk.

Fall of the Drum Kingdom
However, Chopper's isolated life in Drum Castle (which he and Dr. Kureha annexed after King Wapol fled) would one day come to an end with the arrival of Monkey D. Luffy and his pirate crew. Chopper, naturally distrustful of humans, was not pleased, especially given Luffy and Sanji's desire to cook and eat him.

But when Chopper showed both his medical capabilities and his skills in battle against the returned forces of King Wapol, Luffy offered (forces) him the (as-yet unfilled) position of Ship's Doctor in his crew. While Chopper was at first unwilling to leave, he remembered Dr. Hiluluk wishing Chopper to sail seas to see the world on his own and with his desire to broaden his medical horizons, he decided to join Luffy and his crew.

Fleeing the castle with the Straw Hat Pirates, Chopper was given a send-off of gigantic proportions: Kureha had turned the snow into sakura blossoms, the very same that Hiluluk had researched over 30 years that would one day, cure the people of Drum of their "sickness of the heart," passed to Dr. Kureha as one of his last request before death. Overcome with tears, Chopper made a fond farewell to his birthplace and mentors, setting out to sea for the first time in his life.

War in Alabasta
In Alabasta, Chopper distracted Crocodile while Sanji freed the rest of the crew, but found themselves trapped yet again. After escaping from Rain Dinners, Chopper and the crew together with Vivi crossed the desert to Alubarna, where the final battle would take place.

Crocodile, however, managed to catch Luffy, beginning the first round of their battle. The crew, excluding Luffy, proceeded to Alubarna. As they reached their destination, they split up to distract the Baroque Works agents to engage their battle separately. At first Chopper was paired with Sanji when the two were pursued by Mr. 4 and Miss Merry Christmas, until Sanji left to check up on Usopp and Chopper had to fight by himself for a short while until Usopp came to assist him. The battle of Usopp and Chopper vs. the Mr. 4 team then begins.

Things looked hopeless for Usopp and Chopper as they continued to suffer from every attack that the Mr. 4 team made. When Miss Merry Christmas told them that Luffy is dead, Usopp refused to believe it, claiming that Luffy will become the next Pirate King. When she laughed at this, Usopp told Chopper that a real man never lets his friend's dreams be laughed at and must fight for it no matter what. Albeit severely beaten and bruised, Usopp and Chopper finally defeated the Mr. 4 team.

Later, the Straw Hats hurried to locate the bomb before it went off. Vivi figured out where the bomb was, and had Usopp call the Straw Hats together with a flare. She found it inside of the clock tower, but the Mr. 7 pair of Baroque Works were there. Vivi defeats them but realized the bomb couldn't be stopped so easily. It had a timer, and right before it blew up, Pell showed up and took it into the atmosphere, where he sacrificed himself to save Alubarna.

The Rebel and Royal armies continued to fight even after the bomb went off. It isn't until it rained and Crocodile was revealed to be one behind the drought that they stopped. Tashigi and Smoker both are rewarded for taking on Crocodile, but neither one of them believed it was right since the Straw Hat pirates did all the work. Luffy rescued Nico Robin and Cobra from the collapsing tomb where he fought and defeated Crocodile. He was then brought to the palace to rest. When he awakened, a banquet is thrown for the pirates. They were then invited to enjoy the hotspring steam-room inside the palace.

Later that night, Mr. 2 Bon Kurei contacts them, telling them he prevented their ship from being taken by the Marines. The next day, the day of her speech, Vivi was to make a decision on whether or not she will stay with the crew. Meanwhile, Bon Kurei and his crew helped the Straw Hats escape from Hina so they could get to Vivi, who declined joining them for the sake of her country. Regardless, they all showed their 'X' mark to signify that they will still consider her as one of them. After escaping from the Marines, Nico Robin (Ms. All Sunday) appeared from inside of the Straw Hats ship. She managed to persuade the crew to let her join since she has nowhere else to go.

Rumble in Jaya
Nami's Log Pose began to point to the sky, after that, a big ship fell from sky and the crew found a map in of an island named 'Skypiea' on a 200-year-old ship. They competed with the monkey-like Masira's salvage crew while they searched for more clues on how to get there. The Straw Hats decided to go to Jaya island to look for information on Skypiea. The Straw Hats met with Montblanc Cricket on another part of Jaya; Cricket is a descendant of Montblanc Noland, an infamous "liar" who told of a gold city on Jaya, and Cricket was outcasted for looking for artifacts of the gold city. He might have be the only person who knows how to get to Skypiea.

Cricket explained how the Straw Hats can ride a dangerous vertical current called the Knock Up Stream to get to Skypiea. However, they first had to catch a South Bird to point them toward the point where the stream will erupt from the ocean. While the Straw Hats were looking for a South Bird, Bellamy and his crew attacked Cricket's house, and stole the gold artifacts he'd collected over the years from his salvage work. When the Straw Hats returned and see what happened, Luffy decided to take a side trip back to Mock Town. The Going Merry is refitted by Masira and Shoujou to be more flight capable, and the Straw Hats catch a ride on the Knock Up Stream for Skypiea.

Adventure in a Sky Island and Taking Down a God
They started from entering the Gate of Heaven. First they had been recommended by an old woman to pay their extol, but they didn´t have to pay the old woman and she let them pass. As they were carried by a sky shrimp, they landed on a place that's surrounded by clouds. There they met Conis, a Skypiean. As their conversation about the waver continued, the White Berets interrupted them and labeled them as a criminal of illegal entrants. As Chopper along with Zoro, Nami and Robin boarded the ship, the shrimp suddenly carried them, they tried to escape, but that was impossible because of the skyfish behind them. The shrimp left them in the Sacrificial Altar. Zoro, Nami and Robin explored the land and left Chopper as to guard the ship.

As he guarded the ship Shura, one of the priests suddenly appeared to eliminate him. He fought Shura with his ability but found himself no match for the priest. He whistled the whistle to call Gan Fall. As Gan Fall appeared, he fought Shura but in the end, Gan Fall is defeated. Gan Fall fell into the water surrounding the altar and Chopper jumped in to save him but failed due to him not being able to swim. Both Gan Fall and Chopper were saved from drowning by the giant south birds. Chopper is then told by the birds that Gan Fall is the former god. As the crew reunited, he is seen healing Gan Fall. They spent a night on the ship to regain more energy.

The next morning, Chopper explored the island together with Luffy, Zoro, and Robin to search for the gold, but a giant python named Nola attacked them, causing the group to split up. After finding himself all alone, Chopper was caught in the cross fire between Enel's enforcers and Shandians. Chopper eventually found himself on the Ordeal of Swamp where Gedatsu, one of the priests was. He mustered up his strength and defeated Gedatsu. Confident on being on his own, Chopper proceeded to the Upper Yard, but he encounters Ohm, who defeated him. He later regained consciousness when Luffy finally rang the bell.

Later he was seen joining in the celebration. The next day, the crew has collected a large amount of gold from Nola´s body when a group of Skypieans arrive with Robin bringing a large gold post, but the rest of the Straw Hats mistake it for a large cannon and they start running to their ship. They manage to return to the Blue Sea with the help of Pagaya and Conis.

The Davy Back Fight
Chopper and company came across a mysterious pirate ship after trying to escape a giant wave. Soon, they arrived on an island inhabited by strange animals. The Going Merry was captured by the Foxy Pirates. After Tonjit re-united with his horse, they were attacked by Captain Foxy and his subordinates, who challenged Luffy in a Davy Back Fight, a contest of pirates where the stakes are members of the crew.

The first round of Davy Back Fight involved a race around the island with tiny boats. In the anime, Chopper was teamed up with Zoro, and their boat was eliminated immediately. With only Luffy, Nami, and Porche's boat remaining, it was an all out war to the goal, but after Foxy exposed his Devil Fruit powers, Porche won and took Tony Tony Chopper from the crew.

When Foxy decided to take Chopper after the first round, the "Donut Race," Chopper cried, saying that he only went out to sea because he knew that his crew would be the Straw Hats. Zoro lectured Chopper, telling him that he must be a man and that he is responsible for becoming a pirate.

Then the contest began with the second round. Without Chopper, Sanji and Zoro had to face the Foxy Pirates in a ball game, but were hampered by their blatant cheating and the crooked referee. The bickering rivals Sanji and Zoro managed to overcome the opposing team by working together. Luffy takes Chopper back. (In the anime, Luffy chose Shelly instead of Chopper.)

Luffy and Foxy faced off in the final game: a battle of brawn aboard Foxy's ship. The Straw Hat pirates watched from the side as Luffy continued to battle Foxy with the odds not in his favor, and the fight continued inside Foxy's ship. They had not seen the battle when they fight inside the ship. Luffy managed to finally defeat Foxy by using his own ability against him. After Foxy's defeat, the Straw Hats left in search for a shipwright.

Water 7: A Breaking Ship, a Breaking Crew
After the Going Merry narrowly escaped being hit by a "sea train," the crew met an old woman, Kokoro, and her granddaughter, Chimney. Kokoro gave Luffy a map to Water 7. When they arrived there, Chopper had lost Robin when they were out shopping.

Chopper, along Luffy, Sanji and Zoro followed Usopp's bloody trail to the Franky House where they found him passed out in frontof the building. The four of them challenged the Franky Family only to find out that their real target, Franky himself, was gone and had taken the money with him.

After an argument between Luffy and Usopp broke down into a fight, ending with Usopp being greatly wounded by Luffy, Chopper attempted to go to his aid. Sanji tried to stop him, though, saying that Usopp asked for the duel, and getting healed by Chopper would only bring him shame. Despite Sanji's request, Chopper went to Usopp, leaving behind medical supplies as he tearfully ran back to ship.

The Straw Hats got themselves a hotel room. An incredibly high tide called the "Aqua Laguna" was coming and Chopper and Sanji rushed to warn Usopp. While the crew hid from angry residents, Sanji and Chopper discovered Robin and she told them what they've feared: she's responsible for Iceburg's assassination attempt and she wanted to part ways. Chopper reunited with the others without Sanji and they discussed what had happened. Luffy decided that in order to know the full truth, they had to catch Robin.

The Straw Hat Pirates and Paulie broke into the room where they found Iceburg and CP9. Luffy and the others requested that Robin comes back to the crew. She refused and told them that she cannot accomplish her "wish" if she were to stay with them. Robin turned to leave and CP9 tried to hold the pirates back. Robin successfully escaped and Lucci showed the remaining his "transformation". Lucci's transformation was a result of a Devil's Fruit; a Zoan Type leopard. He quickly disposed of the crew and CP9 tied up Paulie and Iceburg, leaving them alone as the building burned down around them. Chopper escaped the burning building with Paulie and Iceburg on his back and collapses outside. Nami rushed to tell Chopper so they can could look for the rest of the crew.

Chopper found Zoro and handed him the Sandai Kitetsu so that he could can escape the chimney he got stuck in. Seeing how determined Luffy was to save Robin, Kokoro and Iceburg lend the Straw Hat crew the use of another sea train, Rocket Man. The Franky Family showed up, pleading to Luffy to let them join them because they'd do anything for their leader. The Rocket Man finally made it out to sea. Paulie told his fellow carpenters who the real culprits were. The Straw Hats, Franky Family, and Galley-La Company then formed an alliance.

They miraculously passed through Aqua Laguna unscathed and the passengers rejoiced. Sanji contacted the rest of the crew and filled them in on his current situation. Back in the Rocket Man, Luffy, Zoro, Nami, and Chopper changed their outfits. Those on the Rocket Man encountered the discarded train carts and Zoro sliced them so they can pass. Zoro also clashed with "Ship Cutter" T-Bone. The fight was short and Zoro joined the crew again in the Rocket Man.

Yokozuna the frog jumped onto the front of the train, knocking them from the rails. After Kokoro spoke with him, he joined the group. Luffy and the others finally caught up to Sanji, Usopp (currently disguised as Sogeking), and the rest of the Franky Family as they neared Enies Lobby. Paulie sat down with the group to talk about their plan. Luffy didn't bother to follow the plan, and proceeded to slingshot himself beyond the gates before the train stops.

Rescuing a Friend from Enies Lobby
As they proceeded to Enies Lobby, Chopper and crew managed to land on Oimo's back. They rode Sodom and Gommorah to reach the Courthouse. As they waited for the bridge to be activated, the Straw Hat´s lined up at the roof to convince Robin to accept their request saving her. When the bridge was not fully lowered, Kokoro helped by using the Rocketman. The train used the half lowered bridge as a ramp. Luffy his crew down as he jumped onto it.

After they crash-landed, Fukuro appeared and declared that a key is needed to uncuff Robin's cuff. The crew decided to individually search for and fight an agent, leaving Luffy to handle Lucci whom Fukuro said was taking Robin to the Gates of Justice. Later, searching for agent, Chopper found Zoro and Sogeking being chased by Kaku and Jabra cuffed each other. He was sent to search for the number 2 key from the other agents.

He switched with Nami to fight Kumadori. As the second Rumble Ball did not work properly, he was beaten initially beaten by his opponent. Desperate, he defeated Kumadori by eating a third one. Causing him to grow into a giant monster, he also lost his rationality and conscience in the process. He was later shot by Franky's "Coup de Vent" which sent Chopper soaring sea in order to stop Chopper's violent rampaging and to change him back to normal.

He had been carried by Kokoro after he got saved by Franky. When he woke up, he and his crew mates had been saved by Kokoro from drowning, who turned out to be a mermaid. As his crew mates defended their get away ship, he could not move his body because of the side effect of the overuse of the rumble ball.

With the help of the Going Merry, everyone managed to escape Enies Lobby safely. However, after escaping, Iceburg arrived in a Galley-La company ship just in time to pick up the Straw Hat Pirates as the Merry suddenly broke apart. Luffy then gave the Going Merry a viking funeral by burning the ship as the crew tearfully said goodbye.

2 weeks after the events of Enies Lobby, Chopper received his first bounty of 50, he was given a low bounty because he was perceived to be the "pet" of the Straw Hats. Chopper was shocked and disappointed that his bounty is so small, since he believed he fought like a man.

When Monkey D. Garp attacked and Usopp tried to rejoin, Chopper was the only one who did not deny his attention.

Adventure on Ghost Island
After sailing for some time on the Thousand Sunny, Chopper and the rest of the crew came across a mysterious barrel floating on the ocean. Upon opening it, a flash shot up from it. After braving a storm that mysteriously came afterwards thanks to Nami and Franky,Chopper and the rest of the crew found themselves in the presence of a ghost ship.

This ship apparently belonged to a skeleton named Brook who initially accepted Luffy's offer to join the crew. Chopper along with Usopp were exceptionally afraid of the skeleton. Just as Brook was about to perform before Usopp and the rest of the crew after dinner, a ghost appeared, and a clanking noise was heard. These sounds were caused by the gates of the island that suddenly appeared, Thriller Bark, closing. This prompted Brook to head to the island before Chopper and the rest of the Straw Hats' eyes.

With Luffy's resolve to go to the island, to which Chopper could not do anything. With Usopp and Nami, he set out in the new 'mini-merry' ship to explore Thriller Bark. There, the three met the Cerberus, which chased them until they hid in a tree. Here the three met Hildon who decided to take them to met Dr. Hogback. This pleased Chopper as the doctor was renowned in the medical world.

After riding a carriage with Hildon through some woods filled with all sorts of stitched-up creatures, Chopper and his companions were left in the middle of a cemetery. There, they were attacked by some Zombies,and escaped into Hogback's mansion and met with the good doctor and his maid, Victoria Cindry. Over dinner, Chopper asked for the doctor's autograph and a chance to visit his laboratory. The former request was given to Chopper but the latter was not.

After dinner with the good doctor in which the three asked about Brook, Nami decided to take a bath. For this, Chopper and Usopp were put in charge of guarding her from intruders from the outside. In the middle of the bath however, Nami was attacked by an invisible thing. Luckily, Usopp an Chopper came in the bathroom and drove it away. Later after the incident in the bathroom, Chopper and his companions found out that the paintings and taxidermy in the dining room were all Zombies. Fortunately, the three escaped through a secret door before the Zombies could catch them.

Beyond the secret door, Chopper and his companions found themselves in a room filled with Cindry's pictures. Through a newspaper article that Nami found, the three learned that Cindry was an actress that died ten years ago. Just as they were about to leave, the three stumbled across a treasure chest. Inside however, was a horrific Jack in a box that frightened the three out of the room.

As the three were running through the hallways of the mansion from more painting Zombies, a mysterious bodyguard decided to chase them.

Eventually, Chopper along with Usopp and Nami hid inside the stuffed body of Kumashi to overhear Moriah's plan for creating Oars- the strongest zombie. Eventually the trio were discovered and made a run for it, but were surrounded and attacked by a large group of Zombies. During the battle, Nami was captured by Absalom. Franky and Robin arrived just in time to finish off the zombies. After that the crew made it's way back to the Thousand Sunny where they found Luffy, Zoro and Sanji. After explaining the situation to them, Luffy ordered the Straw Hats to prepare for a counterattack on Thriller Bark.

When Robin, Chopper attacked Hogback in his laboratory, they found him protected by Jigoro, Inuppe, and Cindry. Chopper and Robin fought them, but were eventually forced into submission. Chopper announced his disgust and defiance by declaring Hogback was no longer a doctor to him. He explained that when Hogback told him he was using the zombies to investigate the difference between life and death, he admired him because he could help those who lost loved ones when death occurred, but when he found out his role in the zombies' resurrection, he was disgusted that he would go as far as to use them for personal benefit instead medical science, and is forcefully moving them despite their hearts not beating, making them puppets. This, Chopper explained is why he cannot accept the zombies as living creatures, and Hogback as a doctor.

Hogback laughed and insulted Chopper's ideals, declaring he brought new life to the zombies and they should be grateful for "reviving" them. He demonstrated their proof of being "alive" by kicking Victoria Cindry in the face and ordering her to lick the ground. He explained that the room that Chopper went into earlier was his room, and told him how he disappeared, and the truth behind Victoria Cindry and her death.

He explained that because of his medical genius, many flocked to him with the hopes he could help them or their loved ones. Eventually, he could not be bothered with that, and explained it was only for the money. Then, a beautiful and famous entertainer named Victoria Cindry became one of Hogback's patients. Hogback, like many other men, was smitten by her beauty and fell in love with her, but she told him she was already engaged. However, it was nothing compared to his eventual heartbreak when he found out Cindry lost her life when she fell from a stage. A depressed Hogback left his job and disappeared from public knowledge, but was discovered by Gekko Moriah and became in his servitude in the promise that Cindry be brought to life.

Eventually, he stole Cindry's corpse and with medical surgery and Geko Moriah's Kage Kage no Mi ability, Cindry was brought back to life as a Zombie. Hogback declared although Cindry had a different personality, he cared only for her beauty and said she is and should be thankful for her resurrection, and thus ordered her to attack Chopper.

While Chopper refused to attack her, and merely restraining her, as she continued to assault him. Chopper pleaded to Cindry to stop and look at what she's become. While she calms down, Chopper asks to Robin to use her powers and feed her salt. However, she was prevented from doing so by Jigoro and Inuppe under Hogback's orders. Later, it soon became apparent that the two zombies could not get along and began to fight each other, just like Zoro and Sanji so Robin took advantage of Hogback's orders by forcefully closing his mouth, asking him to order herself and Chopper to "jump off the tower." When Robin released Hogback, he indeed did give this order, but it was mistakenly given to Jigoro and Inuppe and they followed suit.

Chopper decided to pummel Hogback, as the mad scientist desperately gave orders to Cindry to buy him time, but she miraculously started crying, and said she could not move. Just as the battle was turning in the Straw Hats' favor, with Chopper with Robin's help about to deliver the final move on Hogback, Oars however, demolished the wall and interrupted the fight. As Hogback pleaded for Cindry's help, she simply smiled, implying her soul temporarily returned to her, and leaves him and herself to their fate. Oars' rampage apparently lead him to crush both Hogback and Cindry.

Chopper joined the crew's battle against Oars, and although the battle was completely drastic, it became increasingly desperate when Gekko Moriah used his Kage Kage no Mi ability to manipulate Oars' body, giving him an ability to stretch like his counterpart, Luffy. Despite to Oars' immunity to pain, Chopper discover that his weak spot is his right arm. It was discovered that Oars suffered a severe case of frostbite, due to wandering the Frozen Continent with very little clothes on.

Chopper, Sanji and Zoro continued their attacks towards Oars' right arm, taking advantage of Oars' inability to feel pain, and giving his right arm considerable damage (though not initially noticed by Oars), however Chopper along with Sanji were knocked out for these efforts. With the Straw Hats falling one by one, Luffy returned to save Nami and Usopp and with 100 shadows in him, Luffy strength had multiplied several times over becoming "Nightmare Luffy" and began pummeling the zombie giant, beating him severely, with Moriah himself caught in the attack, before powering down.

Down, but far from out, Oars got up to do battle again. Fortunately, Nightmare Luffy's attack was more than enough time for the Straw Hats to recover. Luffy himself surprisingly got up despite having the exhausting process of 100 shadows in his body for ten minutes. Chopper concocted a plan to force Oars' back straightened to take the full force of Luffy's attack. With his arm broken, Oars could not counter as Luffy activates Gear Third smashing a Gomu Gomu no Gigant Bazooka to his face, breaking Oars' back.

However, Moriah returned to consciousness, and used his ultimate technique Shadows Asgard, taking in all shadows in Thriller Bark, numbering to 1000 to finish off the Straw Hats once and for all. However, as Chopper witnessed, Luffy activated both Gear Second and Gear Third at the same time, and finally defeated Gekko Moriah, releasing all the shadows. Nami then remembered Kuma is on this island and tells everyone.

Meanwhile, Kuma reported that Moriah had failed to kill Luffy and is badly wounded, he was ordered to kill everyone on Thriller Bark and evacuate the wounded Moriah. However, instead of outright killing everyone as his orders said he offered everyone a deal- let him kill Luffy (who cannot fight back now) and he wiould leave everyone alone. The Straw Hats and everyone else on the island told Kuma "no way" and he set off a bomb made out of air that knocked everybody unconscious.

However, before he could finish off Luffy, Zoro rose again and vowed he will not let Kuma touch him, Kuma offered to just kill Zoro then and attacks him, though Zoro survived. Zoro offered his head for Luffy's and Kuma decided to torture Zoro by giving him all the pain and suffering Luffy had endured during the battle. Kuma then left, praising Luffy for having such good friends.

Soon after, Chopper joined everyone in a celebratory party at Thriller Bark (save for Zoro, who was still recovering from his wounds) lead by Brook and his piano. Luffy finally revealed to Brook that he is friends with Brook's friend, Laboon. Brook stopped partying, cried, and revealed a Tone Dial which contained the last song the Rumba Pirates ever performed together on it. Brook stated that since he has found new friends in Luffy and the others, he no longer needed the Dial and would give it to Laboon the next time they meet. Brook then asked if the Straw Hat crew invite is still good and Luffy says it is, Chopper joins the others in a shocked response.

Once he and the rest of the crew finally left Thriller Bark, they held a toast to Brook, their new crewmate.

Strong World
On board the Thousand Sunny, the Straw Hats read news of attacks on East Blue. Luffy said they will return to East Blue to protect it when Shiki's ship appeared overhead. After warning him of the storm ahead, he came down to meet them. There he revealed he has a Devil Fruit power to make any inanimate object he touches ignore gravity and float. After learning it was Nami that delivered the warning, and that they are headed to East Blue, Shiki offered to take them there and uses his power on Sunny. Together the two ships traveled to the floating island seen before where Shiki suddenly kidnapped Nami. Chopper along with the others tried to rescue her, but by controlling the Thousand Sunny using his power, Shiki escaped them, as well as scattering them among the fragments of the island.

Zoro and Chopper ended up on a snow mountainscape. Upon riding around on a Mammoth Dense, they found and rescue a young girl, Xiao, and are lead to her village. She mistook Chopper for a talking Gorilla and momentarily fainted. Along the way they learned the large poisonous plants, called Daft Green, around the village emitted a stink so powerful that the animals stayed away from it. However, long term exposure to the plants is poisonous to humans, and Xiao's grandmother had fallen ill from it.

Xiao was outside looking for the cure, which is the IQ plant, and managed to find one, but Shiki had taken all the IQ plants for his experiments. They met up with Sanji and Usopp, also at the same village, where everyone appeared to have small wings on their arms, they learned that Shiki also took all the men and young women to his royal palace, leaving the village with only the very young and old with strict monitoring around the clock. When the rest of the crew showed at the village, Robin informed them of Shiki's plan. They learned there that Shiki is planning to let loose the animals on the island into East Blue in a gambit to force the surrender of the World Government. They also learned that to prove the power of the animals he is planning a demonstration using a village on the floating island.

Shiki then arrived sometime later and confronted the Straw Hats who were there. Chopper attacked with Arm Point: Kokutsei Roseo Mete, landing multiple blows to Shiki's back, but only mildly hurt him. Despite some initial success in the others fending him off, Chopper and the Straw Hats were defeated, and Nami was coerced into rejoining Shiki by him agreeing to leave them, and her home town be. Usopp, the only remaining crew member conscious tried to stop her, but Shiki knocked him out.

Xiao reappeared and gave them the Dial Nami left them. Her mother, who earlier had expressed relief about the animals being sent to East Blue, apologized for saying how happy she was for Shiki leaving for East Blue. They then played the message, and after hearing only the first bit of it, Luffy was angered to the point that he will not listen to the rest (the rest of the crew did, however).

Back at Shiki's place, Nami is found to have in fact been attempting to blow up the plants protecting his palace, but was overcome by the poison. Shiki trapped her near the plants and headed off to meet the pirate captains gathering. The Straw Hats arrived at his palace and burst down the gates and made short work of the guards outside. While preparing a toast to the commencement of the operation, the Straw Hats marched into the main meeting room brandishing various firearms and a new wardrobe.

After a short confrontation, where Shiki called them simply a suicide squad, and revealed hundreds of men around them. They unload their firearms in the room, defeating most those gathered much to Shiki's dismay, then split up to defeat the rest. Luffy chased after Shiki, with the others helping fight off his minions and soldiers. Usopp and Chopper went off to try and rescue Nami. Chopper tracked her smell to the forest where she was slowly dying from the poisonous toxins. They found her but were hit by some explosives that destroyed the surrounding trees. They quickly grabbed Nami and escaped from the horde of giant animals that began their onslaught towards Shiki's fortress.

Usopp and Chopper began their search of the fortress for the science laboratory to retrieve the antidote. Shiki showed up and stops them, surrounding them with is devil fruit abilities. Luffy then appeared and stopped Shiki, as the two escaped with Nami in tow. They later found the laboratory and broke in, finding a grow up of IQ Plants. Dr Indigo appeared, laughing at them. Chopper says he recognized him as a scientist from the smell of chemicals on him. Usopp demanded him to hand over the antidote, but he refused. Zoro showed up and challenged Indigo for the antidote. He easily finished him off and retrieved the antidote for them.

When Nami woke up, Usopp consoled her, explaining that the antidote is working on her and everyone is fighting for her sake. Nami then ordered the two to backtrack to the royal palace. There, Usopp and Chopper threatened one of the remaining scientists to have Shiki move the island into a storm cloud. After Shiki is defeated by Luffy, Chopper along with the other Straw Hats escape using Thousand Sunny, using Shiki's pirate sail as a parachute. When Nami awoke some time later from Chopper's care, he tells her she recovered alot quicker than he thought but asked her not to push herself too hard. He then tells everyone of Nami's recovery.

An Incident with the World Nobles
After leaving Thriller Bark, Chopper assisted the other Straw Hats on their continued journey. He helped with the battle against Flying Fish Riders alongside the crew.

Afterwards, he arrived in the Sabaody Archipelago, where he joined in the initial group heading out on the island. He was treated to cotton candy by barmaid Shakuyaku and eventually dozed off alongside Brook after trying and failing to find the assisting Keimi. Usopp later found him and Brook and was berated for relaxing instead of looking for Keimi, and they were quickly taken aboard a Flying Fish with the Rosy Life Riders.

After they entered the Human Auctioning House, Keimi had already been sold to Tenryubito Saint Charloss in an extravagant bid of 500,000,000. However, Luffy's Flying Fish burst in, and he quickly got off to rescue Keimi. In former enemy Hatchan's attempt to restrain him, he inadvertently revealed he is a fishman and was shot by Charloss Sei. An enraged Luffy responded by punching him in the face, and started an incident attracting several Marines to the Human Auctioning House. Luffy, along with his and the crews of two of the Eleven Supernovas, Eustass Kid and Trafalgar Law cleared the incoming masses of Marines, Chopper assisted them in battle, until he as well as the rest of the Straw Hats with the help of Duval's Rosy Life Riders, managed to escape.

Destruction of the Straw Hat Crew
Chopper heard Rayleigh's story with the others, but shortly after leaving, he and the others were confronted by a Pacifista. Chopper's Roseo Meitel attack did very little damage to the weapon's defenses, but the group managed to defeat it by combining their efforts. Unfortunately, they were soon confronted by a second Pacifista and Sentomaru, Dr. Vegapunk's bodyguard. Luffy ordered the crew to split up, and Chopper went with Luffy and Robin. Sentomaru intercepted Luffy and managed to wound him with unarmed attacks despite his rubber body.

Seeing his companions defeated, Chopper became desperate and used three Rumble Balls at once, although he had already used one against the marines outside the Human Auctioning House and another against the Pacifista, it transformed him into Monster Chopper. Monster Chopper then began attacking Sentomaru as Robin fled with Luffy. He turned his attention to Kuma who just had appeared and was vanished as a result.

Straw Hat Separation Adventure: Torino Kingdom
Chopper landed in the Torino Kingdom, in the South Blue, where the natives wanted to cook him. As seen in the Straw Hat separation serial, Chopper was running for his life to avoid getting eaten. At some point, he managed to hide while the natives were fighting the giant birds on the island.

After some time on the island, Chopper managed to stop the war between the humans and birds, using his ability to talk to animals to translate for the natives. Afterwards, he left the island worried and wanting to heal Luffy's wounds after learning of his involvement in the war and Ace's death. He flew off the island on one of the birds, though at the same time a News Ku passed by, and after reading the paper Chopper was shocked by a recent article involving Luffy.

He stated that he understood why Luffy was praying at Marineford, and afterwards, he returned to the Torino Kingdom to become stronger. Since Chopper is uncomfortable with returning to the island sooner than expected, he wore a disguise called "Chopper Mask". However, the natives instantly recognized Chopper and the reindeer then threw away the disguise.

Chopper said that he wants to study the plants on the island and a native took him to the village library where he could do his research. Chopper then commented that the natives are not as primitive as he originally thought as he recalls them using mechanical weapons. Chopper then thought back to his early days, where he was called a monster and shunned by everyone. He realized that ever since he joined Luffy's crew, it did not matter what other people called him, and he promised to help Luffy no matter what.

The Straw Hat Reunion
After two years, Chopper returned to Sabaody Archipelago. Chopper was seen following Fake Zoro, Fake Sanji, Fake Robin, and his own counterpart, believing them (excluding Fake Chopper) to be the real ones. After Fake Robin tried to lure Chopper to them with a cucumber, Chopper then witnessed the fake Robin getting kidnapped by some mysterious men. Later when he saw the Impostor Straw Hat Pirates, he was disappointed in his "captain" because they were not going to save "Robin", and he left crying and saying that he would save her himself.

While searching for "Robin", Chopper ran into Usopp and Nami, who were very happy to see him. After Chopper was informed that the Straw Hats he encountered were fakes, he returned to the Thousand Sunny with Usopp and Nami. Franky then amazed Chopper and Usopp with his new upgrades. Chopper got excited wondering what Franky's new weapons are. He was pleasantly surprised when he heard from Rayleigh that Luffy was already in the archipelago.

After arriving at Grove #42, Chopper departed atop one of his enormous bird friends from Torino Kingdom to bring Luffy, Zoro, and Sanji back to the Thousand Sunny. With the assistance of the Straw Hats' new allies, Chopper and the rest of the crew descended into the ocean with their coated ship, finally resuming their adventure after two years.

Undersea Voyage
While sailing under the ocean, Chopper and the crew marveled at the site of the underwater world. He and Usopp also had to keep Luffy and Zoro from doing anything that might endanger the crew. He attended to Sanji after the he recieved a massive nosebleed. Chopper along with the rest of the crew decided to have lunch, while Franky explained how their ship was in one piece after two years thanks to Kuma. As the ship descends even deeper, the crew marveled at how dark it has become. With their seacow, the Caribou Pirates soon caught up with the Straw Hats and prepared for battle. Caribou jumps onto the Thousand Sunny. Before his crew can follow, his seacow, which turned out to be Mohmoo fled in fear after seeing Nami, Sanji and Luffy, leaving Caribou behind. The Straw Hats then tied up Caribou as he begged for mercy. Caribou claimed that he is an unfortunate victim and not a pirate, Chopper believed him until Usopp pointed out that he is lying.

Chopper then attended to Sanji as he experiencend another massive nosebleed, suggesting that they try to rehabilitate Sanji. He listened as Nami, with the help of Brook, Franky and Robin explained about the Sea Currents, but quickly lost interest when Nami starts talking about how salinity affected them.

He reacted with shock when he saw the Kraken. He then screamed in terror when he witnessed the Kraken destroying Caribou's ship. Even though the Monster Trio left the ship using Barefoot Coating to fight the Kraken, the sea monster aimed for the Thousand Sunny. Franky used his rocket launcher to repel one of the tentacles which amazed Chopper, Ussop and Luffy.

Chopper then blocked another tentacle with his new and impoved Guard Point. The Monster Trio soon defeated the Kraken, but because they were not wearing life-lines, they got separated from Chopper and the rest of the Straw Hats as the ship went down the underwater current.

When the crew reached "The Underworld of the Sea", Chopper immediately started to look for the missing Monster Trio along with Usopp and Brook. He then noticed the gargantuan size of a school of jellyfish that were floating around the ship. One of the jellyfish put one of its tentacles through the bubble coating. Chopper reached out to touch it but Robin stops him, saying it is probably poisonous, much to Chopper's stunned surprise. When an even larger fish ate the jellyfish he almost touched, it died as a result, confirming to Chopper that Robin's theory about the jellyfish probably being poisonous was correct. The reindeer commented on how scary and dark the Deep Sea is and how the fish in it cannot see too well.

When the crew realized Caribou was gone, Chopper thought one explanation was that he was thrown overboard while going through the downward current. Chopper was scared when Nami suggested that Caribou might still be hiding on the ship. After Franky trapped Caribou in the barrel, Chopper was the first to notice a sudden rise in temperature. He then moaned about how hot it is, saying he could not go on living like this way, and how after waiting two years to see Luffy, Zoro, and Sanji, they disappeared. When the ship is about to be eaten by a gigantic angler fish, Chopper foams at the mouth in shock.

When the under-sea giant, Wadatsumi appeared, Chopper started to cry from sheer terror. He screamed in fear when the Flying Dutchman appeared. He, along with Usopp, was shocked by Brook's frightened reaction to the ghost ship. He was shocked to see Surume suddenly show up and knock out Wadatsumi, and overjoyed with the rest of the crew to that the Monster Trio came back safely. When they were on board, Chopper tackled Luffy, telling him how scared he was.

When the underwater volcano started to erupt, Chopper panicked and was thrown back by the rest of the crew. Chopper exclaimed how hot it was when Nami said the water temperature was rising. When Sanji suffered a nosebleed while talking to Nami, Chopper remarked that it was a bad time to have a guilty conscience. When the crew reached the trench, Chopper noticed how the water was making steam from the heat. When the rocks fell into the trench, he marveled at Usopps new attack. When a stray rock hit Surume, Chopper fell with the rest of the crew to the bottom of the sea.

Upon finally reaching Fishman Island, Sanji suffered another nosebleed thinking about mermaids. Chopper told him that it would be best if he did not see any actual mermaids, as doing so could kill him. He was impressed with Sanji's fiery resolve to die while seeing mermaids. When Hammond approached with his group of sea monsters, Chopper is shocked by their gargantuan size. Hammond gave the crew two options: join the New Fishman Pirates or die. Chopper and the rest of the crew then prepared to enter Fishman Island with a Coup de Burst.

Trouble in the Underwater Paradise
Luffy rejected Hammond's offer of joining the New Fishman Pirates and the fishman prepared to attack. Franky activated Coup de Burst and the ship flew through the bubble surrounding Fishman Island. The ship then fell into a current and the crew got separated. Chopper, Luffy, Sanji, and Usopp were seen again in Keimi's house meeting and getting reacquainted with Keimi. Keimi introduced them to some of her friends, the Medaka Mermaid Quintuplets and took them to Mermaid Cove where they met more mermaids.

As Sanji swam with the mermaids, Luffy, Usopp, and Chopper relaxed. Chopper expressed his surprise that Sanji is back to his normal self, wondering if it was in the chef's nature. He also said that he is glad that Sanji was feeling better, as he had run out of Sanji's blood type in his blood stock. Chopper statds that Sanji has a rare blood-type and that he would not be able to treat any more nosebleeds. While Keimi was telling Luffy that Jinbe is not present on Fishman Island, Chopper was seen in the background looking shocked at a sea serpent that has just appeared behind Usopp. When the killifish mermaid quintuplets informed them that a royal gondola is approaching, Chopper, Luffy, and Usopp hid behind cover while Sanji was being covered by a mermaid. The three brothers of the Neptune House appeared, searching for the people who entered Fishman Island illegally. The mermaids denied that they have seen any intruders.

As the three brothers are leaving, Sanji suffered his worst nosebleed to date, forcing the Straw Hats to reveal themselves. As the Ammo Knights started advancing, Chopper pleaded for them to stop and help Sanji, asking if anyone could donate blood. He explained that if they do not get blood for Sanji, he will die in half an hour. Chopper asked if there is anyone who has a blood type of S RH-, going on to say that it is extremely rare. Keimi told Chopper that fishmen and merfolk have the same blood as humans and it is transferable. She was about to explain further, but Hammond interrupted her, continuing her explanation. He explained that there has been a rule in place for a long time stating it is forbidden for humans and fishmen to share blood. He goes on to say how Fisher Tiger supposedly died. After a gruesome battle, Fisher Tiger suffered a critical blood lost and could have been saved with a blood transfusion, but humans refused to help him. Hammond adds that the rule was put in place by humans ages ago so that their bloodline would not mix with "monsters".

Hammond and his group attempted to capture the four Straw Hats, but Luffy repelled them. When a sea monster in the New Fishman Pirates tried to attack Luffy, the Straw Hat captain subdued it with Haki. Chopper and Usopp are shocked by how the monster acknowledged its loss without actually fighting. Keimi stole the royal gondola and helped the four Straw Hats escape. After Usopp noticed Sanji's smirk and Chopper yelled at Sanji to not think about anything as every second matters, Keimi then took the group to the town port.

At the town port, Keimi and the four pirates found shelter in Madam Shyarly's Mermaid Cafe. Madam Shyarly provided them a room where they could treat Sanji. Chopper and the others luckily came across Splash and Splatter, a pair of okamas who happily agreed to donate blood to Sanji. After Sanji received a blood transfusion, Chopper is relieved that Sanji was able to wake up. Chopper also noticed that Luffy got a scar on his arm when he attacked Hammond and his two companions. Chopper checked Luffy's blood and see that Luffy got poisoned by the octopus merman and is amazed that Luffy's body was able to fight against it. Chopper stayed with Sanji to ensure his recovery.

When the Ammo Knights tried to arrest him and Sanji because of Madam Shyarly's premonition and because of the false accusation for mermaid kidnappings, along with the fact that the majority of the other Straw Hats were holding the staff of Ryugu Palace hostage, Chopper used his new Kung Fu point to fight them off, something that the soldiers and citizens thought was a weird animal. Having slightly recovered, Sanji told Chopper that he was going to see the Mermaid Princess, even if it would cost him his live. Chopper scolded him, telling him that if she was beautiful, Sanji might die instantly.

Sanji then defeated the rest of the Ammo Knights and expressed his disappointment of having to give up his chance of going to Ryugu Palace since they were trying to handcuff him. Chopper scolded Sanji for overdoing things, but Sanji snapped back saying what's done is done. Sanji then complimented him on his Kung-Fu Point and the reindeer happily danced while claiming not to be happy about that compliment. When they heard people screaming that a bloodied person is found and needed a doctor, Chopper turned to their direction and said that he is a doctor. Chopper and Sanji then found a wounded Hatchan, who warned them of an impending attack by the New Fishman Pirates.

Chopper then tended to Hatchan's wounds while the doctor and Sanji are met with accusations from the Fishman Island citizens. While hovering above Coral Hill on top of Megalo, Luffy saw them and jumped down to meet them. Megalo, who was holding Princess Shirahoshi in his mouth, reached his limit and spit her out. While the Fishman Island citizens instantly concluded this as a Mermaid Princess kidnapping, Chopper yelled at Sanji to not turn around or else he might die from another nosebleed.

For the sake of his dream, Sanji decided to turn around even if it means death much to Chopper's horror. However, instead of getting a nosebleed, Sanji became petrified. Chopper said that it must have been the effects of the Okama blood transfer. The citizens then tied up Chopper and the group, but were interrupted by the arrival of Vander Decken IX. After Luffy pummeld Decken into the ground, he checked on Sanji. Chopper informed him that Sanji has reverted to his normal state. The princess and the entire group then hopped on Megalo and flew away. After Luffy knocked back Wadatsumi, the entire group headed for the Sea Forest.

After reaching the Sea Forest, Chopper decided it is safe for him to take his time to treat Hatchan's wounds. The group then got acquainted with Franky, Den, and Jinbe. Chopper then told Franky that he was going to lower Hatchan down from Megalo, and he should be ready to grab him. After Hatchan was lowered, Chopper was surprised to see that Sanji is acting like his old usual self in front of Shirahoshi. Nami and Keimi soon arrived and Chopper happily realized that Sanji is finally cured of his nosebleed tendencies. While Chopper made medicine, he listened to Jinbe as he explained the dark past of the fishmen and merfolk as well as the ideals of Queen Otohime and Fisher Tiger.

After Jinbe finished his story, Chopper and Nami had a friendly conversation with Princess Shirahoshi. When Hatchan started explaining Hody's plan, a visual Den Den Mushi appeared and the group watches a visual broadcast by Hody Jones himself.

Hody explained his plan of recreating the Ryugu Kingdom with himself as the ruler and then addressed the Straw Hat Pirates. Once he showed the imprisoned Zoro, Usopp, and Brook, Chopper is shocked. After Hody finished his speech, Luffy resolved to fight him. However, Jinbe told him not to. Chopper and Franky then correctly guessed that it's because they are humans. Chopper then watched Luffy and Jinbe trying to settle their dispute on how to deal with Hody.

Battle for Fishman Island
Chopper later appeared in Gyoncorde Plaza with the rest of the Straw Hats preparing to fight against the New Fishman Pirates. When Franky mentioned a new weapon in the Soldier Dock System, Chopper got on board it along with Usopp, Nami, and Pappug. He kept asking Usopp if he could drive it. He then rode out on the Brachio Tank V, calling himself "Commander Chopper."

When the Brachio Tank IV fell in a pitfall created by Daruma, Chopper was thrown out with the others by Franky. He then went underground, using his new Horn Point and hindered Daruma in making more pitfalls. He launched him back to the surface and when arrived there, Luffy mistook his new form for a stag beetle. Chopper then faced off against Daruma.

Chopper was underground with Daruma when Usopp called out for him. Dosun got behind Usopp and tried to take him by surprise, but Chopper intervened using Horn Canon: Elf to push Dosun back. While Usopp prepared to fight Daruma, Chopper prepared to fight Dosun.

Later, Chopper commented on the new attack from Iron Pirate Franky Shogun, but was shocked to see that Franky was the attacker instead of the robot. Dosun tried to take advantage of this, but Chopper transformed into his new Heavy Point and matched Dosun's T-Shot with a Heavy Gong. As he recoiled from the force of the attack, Zoro commented on the new monster appearance of the transformation, which Chopper willingly accepted.

Later, Chopper was seen rampaging in his 'Monster Point' much to Usopp's surprise. Usopp nervously told Chopper that the situation is not that serious for him to go like that. Then, Chopper turned to him and says that he is alright, meaning that Chopper was in fact still conscious.

After explaining to Usopp that he can use one rumble ball to stay in Monster form for three minutes, he turned back to Dosun and easily knocks out the fishman with his Kokutei Parmei attack. After all the leaders of the New Fishman Pirates had been defeated, the Straw Hats looked into the sky as Luffy tried to destroy Noah. When the Sea Kings appeared and stopped Noah from falling, saving the ship and the island at the same time, everyone on Fishman Island celebrated.

The After Battle Celebration and Departure
Moments later Shirahoshi brought Luffy to the plaza, dismayed to inform everyone that Luffy had lost a lot of blood. Chopper then asked the citizens if any of them has type F blood. He then recalled the law prohibiting fishman-human blood transfusions. Then Jinbe stepped up and volunteers to donate blood, saying that he doesn't need to follow the law, since he is a pirate. Chopper carries out the procedure.

Luffy invited Jinbe to join the crew, but Jinbe declined, saying that he has some unfinished business. Chopper and the rest of the crew informed Jinbe he is welcome to join whenever he is ready.

Neptune invited the crew to a banquet and the crew partied at Ryugu Palace with the royal family. After partying for a while, Chopper was shown enjoying himself, when Jinbe recounts the conflict between Aokiji and Akainu. Chopper proudly stated he had already heard about it. He then expressed dismay at the statement that the Blackbeard Pirates are hunting strong Devil Fruit users. He believed that he would be a target, but Usopp pointed out that they would not need the Hito Hito no Mi. After the party ended, Chopper was talking with Usopp about the treasure Luffy, Zoro, and Sanji went to collect. He suggested they help them search and was surprised about how high Caribou's bounty is. Chopper and the rest of the crew were later shocked that Luffy challenged Big Mom.

Afterwards, Chopper and the rest of the crew bid the citizens of Fishman Island farewell and promised (except Franky and Zoro) Shirahoshi to take her to the surface someday. The crew began to set sail with the Thousand Sunny and head towards the New World.

On their way to New World, Nami put Chopper to guard while she takes shower using her Shower Tempo. Chopper remarked how the Shower Tempo clouds look sweet and yummy like cotton candy and showed his concern if the crew will be alright with Nami not on the deck. After the crew reaches the New World, Chopper commented on how the sea of New World looks red.

Arrival at Punk Hazard
Soon after entering the New World, the crew spotted an island surrounded by a sea of flames. The Straw Hats then received a distress call from someone who seemed to be in trouble and mentioned something about a samurai. After Luffy decided to go rescue the person, Chopper expressed relief that he was not one of those chosen to accompany Luffy on his exploration mission, stating that he is not good with heat.

While Usopp, Robin, Luffy, and Zoro fought a dragon, Chopper and other Straw Hats that remained on the Thousand Sunny were knocked out by sleeping gas. They, except for Brook, were then abducted by some unknown foes. The captured Straw Hats later woke up in a cell and find parts of a samurai's still-living head. After putting the pieces of the head back together, the group got information from the samurai. Once they decided to break out, Franky used his Radical Beam to blast a hole in the wall, allowing the crew to escape. They ran down through the halls of the complex and stumbled upon a room filled with giant children. The children were excited to see them, but Sanji just wanted to escape the room before they are recaptured.

While their pursuers came after them, the children begged the pirates to help them escape. Nami could not ignore their cries and decided to help them. Sanji, Franky, and Chopper then attacked the men in the gas masks. Nami and Chopper ran away with the children while Sanji and Franky held the enemy back. Since he was entrusted with protecting the children, Chopper was determined to live up to Sanji and Franky's expectations. As they ran, the children tell Nami and Chopper about how they were abducted and that they were inficted with some kind of disease. Nami was suspicious, and told Chopper to later investigate the children. They then ran into a room with corpses frozen in the walls, floor, and ceiling.



Frightened, the group escapes and met up with Franky, Sanji, and the head of the samurai, and they all ran out of the building and into the shocked view of the Marines of G-5, Smoker, Tashigi, and Law. They immediately turned around and tried to find another exit to avoid any combat. As they were running away, Law used his ability to rearrange the personalities of the Straw Hat Pirates, putting Chopper in Sanji's body and Franky in Chopper's body. After escaping, Chopper (in Sanji's body) helped keep Nami (in Franky's body) from hurting Sanji anymore than she can. The group then reunited with Zoro, Luffy, Robin, Brook, and Usopp at the back side of the Punk Hazard facility. The Straw Hats then tied up Brownbeard and bring each other up to speed on the current situation. After interrogating Brownbeard, they learned about a man known as Caesar Clown.

Kin'emon later left the group to find his torso and Sanji, Brook, and Zoro go out to find him. In the meantime, Chopper began to examine the children and the source of their sicknesses, while Franky (in Chopper's body) experimented Choppers abilities and makes weird faces. Before long, several of the giant children started to feel pain, saying that they need candy usually given to them in order to make the pain go away. However, Chopper stated that the candy contains a drug that the children became addicted to and Luffy's group learns that the children have been experimented on. One of the giant children hit Luffy and the others went on a rampage, forcing Usopp to put them to sleep. Chopper expressed his sympathy towards the children and Luffy's group decided to help the children and found Caesar. The group then tied up the giant children so that they cannot destroy anything else. Luffy, Usopp, Franky, and Robin then left Chopper and Nami to watch the children while they head to Caesar's lab. While they were gone, the Yeti Cool Brothers attacked and gunned down Brownbeard. By the time Luffy's group returned, they had kidnapped Nami.

Luffy and Franky decided to go after the brothers. Franky asked Chopper to give him some Rumble Balls. Chopper gave him one and advised him on how to use it. However, Franky immediately took one, transformed into Monster Point, and went on a rampage while chasing after Luffy.

Alliance with Law and a Plan to Defeat Caesar Clown
After the defeat of the Yeti Cool Brothers, Luffy, Franky, Nami, and Law returned to the hideout. Chopper and the rest were shocked that Luffy formed an alliance with Law. Law then returned Chopper to his body and Franky to his. Chopper then scolded Luffy and Franky for causing damage to his body. When the Straw Hats insisted Law to assist them in helping the children, Law asked to take Chopper with him to help find the medicine that was used on the children. Usopp tied Chopper to Law's hat, while the rest laughed at Law. Chopper is then tied to his nodachi instead.

Law later warped both himself and Chopper to the back side of the facility to began their part of the plan. The two briefly discussed on how they are going to investigate the drugs. They were later seen inside, where Law managed to lead Monet away while Chopper (hiding inside Law's bag) is left in the room unnoticed. Chopper then left his hiding spot and started sneaking around in the facility.

He later found Luffy's group in Caesar's clutches. Before Caesar send them outside to die by the poisonous gas cloud created by Smiley, a piece of paper was hurled at Chopper. Chopper then read a note, which told him not to do anything. He is later seen running pass by Caesar's location, planning to escape the facility. Chopper managed to acquire enough information of the drug and even got a sedative. As he ran through the hallway, Monet notices him.

Chopper later met up with Mocha and explained to her about Caesar's deception and using the kids for his experiments and how if Caesar continued to use them, the children would die before they reach adulthood. Mocha remembered her friends promising to each other that when they get older, they would reunite and go on a adventure. The gravity of the situation became clear to Mocha and Chopper promised that he and the rest of the Straw Hat Pirates would save her. While Mocha guarded the candy in the Biscuits Room, Chopper attempted the hold back the children. He later entered Monster Point and was fending off the children in Building B. However, Chopper was unable to fight without hurting the children and was beaten down. When the Rumble Ball wear off, the children ran past him and made their way to the Biscuits Room. At this point, Brook, Kin'emon, Zoro, Nami, Usopp, and Robin came to his aid. Chopper told them that he was trying to prevent the children from getting their candy with the aid of Mocha. The group quickly ran after the children to the Biscuits Room. Regardless of Robin's attempt to hinder them, they went after Mocha, who was holding a piece of candy. After Chopper told Mocha to run, Monet appeared and told Mocha not to keep the candy all to herself and that she should share the candy with the other children.

Chopper and Nami then tended to Robin, but she assured them that her wound was only a cut. Monet tried to attack them when they attempted to run after the children, but Zoro quickly blocked her. After getting hit by Nami's Heat Egg, Monet dove into the snow and stopped Nami, Chopper, and Robin from leaving by creating a wall to block their path. An enraged Monet suddenly ensnared Nami and Chopper and prepared to bite Chopper. Nami swiftly moved Chopper out of harm's way and Robin used her Hana Hana no Mi abilities to shatter Monet, saving Chopper and Nami from another attack. Zoro then cut down the snow barrier, allowing Robin, Nami, and Chopper to go after the children.

Chopper, Nami, and Robin then tried their best to keep the berserk children from catching up to Mocha. While Nami and Robin hinder them, Chopper sedated them one at a time. Despite their efforts, some of the children managed to get around the Straw Hat Pirates and caught Mocha. Having no choice, Mocha put the entire batch of candy in her mouth as Chopper, Nami, and Robin watched in horror. Despite Chopper's pleas, she swallowed all the candy. Mocha then began coughing up blood, due to the serious overdose of the drug. As the children were shocked at what they saw, Chopper yelled at them, saying that Mocha sacrificed herself to save them. As they rushed to Mocha, Sanji and the G-5 Medical Team finally arrived to help. Some of the Marines have Mocha moved to an examination room so Chopper could. tended to her condition. Chopper then complimented Mocha on her bravery and hoped that he can save her.

Nami, Robin, Sanji, the children, and the G-5 with them went on ahead to Building R as Chopper and the Marines with him treated Mocha. Once Chopper was finished with the treatment, they proceeded to Building R as well. They later ran into Brook and a petrified Kin'emon. Once everyone reached Building R safetly, they board a rail car and make their escape.

Aftermath
Sometime after Baby 5 and Buffalo's defeat, Law treated the children's conditions in a nearby tanker. When Chopper thought that Law had done something horrible to the children, he screamed, and repeatedly called Law a murderer. After Law came out of the ship, Chopper demanded to know what he had done to the children, and Law answered by telling him to mind his own business, and that he had just finished cutting them into pieces. Frightened by this blunt answer, Chopper ran inside, and was relieved to see that the children were okay. The kids then told Chopper that Law took out all the "bad stuff" from their bodies and that they felt great, although being cut into pieces was pretty scary. They then talked about Mocha and what she did to save her friends, and asked Chopper if she would wake up. He assured them that she would wake up and that everyone would return home, away from this nightmare. He then left as Tashigi came in and told the children the Marines would take care of them from then on. Later, after Mocha woke up, an overjoyed Chopper hugged her in relief. Everyone then had a feast together.

After the party ended, Chopper and the rest of the Straw Hats began to prepare to set sail again. As they were leaving, Nami told Chopper that Vegapunk would help cure the kids from the effects of the candy. Chopper reacted by saying that it that was very good news. While they made their way, the G-5 marines put up a banner to prevent the kids from seeing the Straw Hats while yelling things like Marines are justice and pirates are scum. The kids, however, said that they were the ones who saved them, while remembering all the Straw Hats did for them. The G-5 marines continued to speak ill of pirates and praised the marines, but Tashigi interrupted them and said that they were a disgrace. The G-5 marines responded by saying that if they did not badmouth the pirates, they would come to admire and respect them. Eventually the marines lowered their voices and banners to let the kids say their goodbyes, while Chopper and the rest of the Straw Hats waved them goodbye, as they made their way to their ship.

Chopper and the Straw Hat Pirates were later seen on a Sea Slope, which Law mentions is pretty common in their current area. A little while later, Luffy started to explain that they formed an alliance to take down a Yonkou. Chopper continued to treat Caesar’s injuries, until he began to say that they are practically making themselves targets to the big shots of the New World. He continued to taunt them, and called them a larger group of idiots and that only death awaited them. Sanji responded by kicking Caesar, which in turn angered Chopper, saying that he was still treating his wounds, and that Sanji could kick him after he was done with that.

Law then proceeded to explain the operations and underworld deals of all the major pirates of the New World and that Doflamingo, also known as Joker, is the one with the most influence in the underworld. Law continued on, saying that Doflamingo's biggest client is Kaido, which greatly shocked Kin’emon and Momonosuke. Law continued to explain the next goal of their plan, which is to cut down Kaido’s forces as much as possible, specifically his army of synthetic devil fruit users. When Law informed the crew that the current number of Synthetic devil fruit users is about 500, Chopper, Usopp, and Nami voted against the plan but without success. Law assured the crew that the number would not grow any time soon, due to the capture of Caesar. Chopper complimented Caesar about his manufacturing of the synthetic devil fruits which made Caesar quite happy and Usopp quite angry. Law then said that it was really Vegapunk that developed a theory on the devil fruits, and that Caesar only applied it, which made Chopper lose all interest in Caesar. Law concluded by saying that the devil fruits are being made on their next destination, Dressrosa, and also warned the crew to not underestimate Doflamingo. Luffy then asked Kin'emon if he had business on Dressrosa and Kin’emon revealed that one of his comrades is being held prisoner there.

Later that evening, Chopper and Usopp went on guard duty while wearing samurai armor. The next morning, everyone read the news about Doflamingo's resignation from the Shichibukai. They saw that the paper also explained Luffy and Law's alliance and the alliance between Kid, Hawkins, and Apoo.

The Next Objective
After Law contacted Doflamingo to inform him that they will bring Caesar to Green Bit, Chopper had a meal with the rest of the crew while Kin'emon and Momonosuke told them the story about how they were shipwrecked and drifted to Dressrosa, how Momonosuke was separated from his father, and how Kanjuro was captured. The Thousand Sunny later approached Dressrosa.

After disembarking, the group splits into three teams. Chopper is part of the team that guards the Thousand Sunny. Chopper freaks out when he sees that Sanji is not part of his group.

Momonosuke later played shogun with Chopper, Nami, and Brook. When Brook started singing a song, they heard strange noises and a voice coming from the men's room.