Tony Tony Chopper/Personality and Relationships

Overview
Chopper is naïve and extremely timid towards unfamiliar humans, often acting like a child because he does not know any better. Like Luffy, he is easily impressed at things like beams, cannons and hidden abilities. He is a coward at times like Usopp and Nami, although his cowardice can be attributed to his childishness and overall lack of trust in his own fighting skills (a contrast to Nami's self-survival based cowardice and Usopp's insecurity based cowardice). He would rather run and hide than fight, but becomes more courageous when others are there to support him. Chopper is more or less on a journey to define himself, seeing almost anyone on his team as a role model and in some cases, imitate their behavior, especially Usopp.

Being the youngest, Chopper is the most emotional Strawhat and very much considers the crew his "family", when forced to be part of the Foxy Pirates during the Davy Back Fight Chopper was distraught and cried that he was a Straw Hat and only stopped bawling when Zoro ordered him to "man up".

After the timeskip, Chopper seems to have grown more confident, much like Usopp. He no longer strives to be looked at as a human, now only wanting to "be a monster that can help Luffy" as he put it. He even has grown mature enough to smack his crewmates, mostly Zoro and Luffy, when they try to do something stupid or extreme. He also seems to have outgrown most habits mentioned above, but his habit of peeking still remains.

Chopper is capable of romance, though he shows no interest in human females e.g. Nami, but he was blushing around the beautiful reindeer mink, Milky, acting in very Sanji-like manner with love hearts replacing his eyes. Usopp noted on this unusual behavior, but Chopper told him to shut up.

Kindness
Immensely kind hearted by nature, Chopper is an upright friend and caring companion who will try anything to overcome a task given by his team. Even back when he was Hiriluk's assistant, he would go to extreme lengths just to acquire a mushroom which he thought would cure Hiriluk's chronic disease.

Chopper seems to be very forgiving of those close to him, for when Usopp wanted to rejoin the crew at the end of the Enies Lobby Arc, he called out to Luffy and Zoro, although they were ignoring him completely.

Doctor's Code
I will be all curing medicine. A doctor that can cure anything. A doctor that can cure countries! Because there is no such thing as incurable disease.

His dream is to carry out his deceased mentor, Hiriluk's belief that there is no incurable disease, and to become a doctor that can cure any illness. To this end, his childish nature vanishes whenever his medical skills are required. He does not hesitate in the least in any actions regarding the well-being of his patients.

A extremely dedicated follower of the Hippocratic Oath, Chopper strongly believe that a doctor's duty is supposed to help save people, and becomes angered when somebody treats life without the proper respect. This was why he was greatly furious at his former hero, Dr. Hogback, when the man treated the patients' and Zombies' lives, and deaths, so callously. He was also utterly enraged at Caesar Clown for kidnapping and experimenting on children as well as making them addicted to drugs. Adhering to his beliefs, Chopper would readily help any injured victims or patients he come across and does it with immense determination. He was determined to help Mocha and the other children who were tricked into becoming test subjects in Caesar's deadly experiments. Similarly, Chopper wasted no time in treating the Mink Tribe after they were brutally devastated by the Beast Pirates. Also, Chopper holds his position as a doctor in high regards and will become distraught if he failed to save someone. When Luffy was on the verge of death from eating the skin of a poisonous fish, Chopper tried every antidote with no success, causing him to claim he had no right to call himself a doctor.

Love For Sweets
Chopper has a sweet tooth and can be just as gluttonous as Luffy when it comes to eating sweets. Alongside Luffy, he was estactic when arriving in Totto Land, which is made entirely of sweets and even devoured an entire chocolate cafe on Cacao Island. While Chopper and Carrot hid inside the gigantic wedding cake during the mission to save the Vinsmokes, Chopper constantly eats it non-stop.

Running Gags
He still has a feeling of distrust for humans from his youth, and will often outright insult and claim that compliments do not make him happy even though he is obviously happy about it (he starts to do the "Dirty Old Man" dance which was a bit by famous Japanese comedian Ken Shimura, which became a running gag). At least once, Chopper has done this dance while in Monster Point, in which case it did not look cute and only managed to disturb Usopp, who had caused Chopper to react this way by praising his newfound usefulness in being able to now control this form.

Another one of Chopper's habits is his reverse cartoon peek, where he stands behind a wall or a doorway and peeks at people, trying not to be seen by them. Unfortunately, he is not hiding his body behind the wall and as a result, his body is visible and only one half of his face is hidden.

A running gag is that Chopper will believe just about anything he hears, making him easy prey for Usopp's stories and his "Sogeking" disguise. He also believed Nami when she lied to Lola about being a man, even though the truth was very obvious. In fact, until Jinbe stated otherwise, he thought that the captain's duty was not to listen to anyone. Chopper also believed the Fake Straw Hat Crew were the real Straw Hats despite them looking nothing like their real counterparts.

He also tends to panic quickly, and subsequently let some crucial facts slip his mind. One example is when there is someone who is injured, he often panics and screams "Call a doctor!!". It is not until he figures out that he is the doctor that he starts to tend to the injured person. Another one is when he (and Brook) jumps into the water without hesitating to save Luffy from drowning, only to drown with him (since the Devil Fruit which he had eaten makes it impossible for him to swim). He, together with Brook and Luffy, ends up being saved by the other members of the crew.

Whenever someone is hungry, Chopper is seen as food source of meat due to his size as people want to eat him, mostly Luffy.

Crew
Notably, Chopper originally was not hired to be the ship's doctor by Luffy, but just for being a "talking transforming reindeer monster". The other boys of the crew have often mentored Chopper on what it means to be a real man, as he is the youngest crewman, not originally human, and has had a relatively sheltered life. Within his combat relationships, he has at least three canon team attacks, and as a homage to his personality (which can be easily influenced), each of the attacks are named with half of the other crew member's name and half of his name. All of the examples feature the fellow crew member's name first in the name then his own such as "Hissatsu Uso-Cho Hammer Suisei" where Usopp's name is the first mentioned.

Monkey D. Luffy
Within the group, Chopper often fools around with Luffy for laughs and is one of the first to join in with Luffy's antics. Although he tends to fool around with him the most, he has also received some of his greatest motivation from Luffy. His mentor Dr. Hiriluk originally introduced Chopper to the concept of being a pirate and the conviction behind the pirate flag, but Luffy was the first real-life pirate that he got to witness, in the Drum Island Arc. He was amazed by how much Luffy as the captain cared for his crew, as demonstrated by the lengths he went to for Nami and Sanji. He was awestruck when Luffy took head-on attacks from Wapol in order to defend the honor of Dr. Hiriluk's flag. Luffy's persistent requests for Chopper to join the crew annoyed him greatly, but it also moved him to see that Luffy actually liked him for his transformations, when his whole life they had led to him being cast out and deemed a monster. Chopper deeply cares for Luffy as he will jump in the ocean to save his captain, despite having to be dragged out too since he's a Devil Fruit user.

After the timeskip, Chopper is more willing to beat up Luffy for stupid decision making but still strongly respects him as captain, as seen when he witnessed Luffy defeat and tame Surume. In Punk Hazard, when the kids were drugged by Caesar Clown, Chopper told Luffy the importance of not letting the kids eat the "candy" and Luffy respected his knowledge as a doctor.

Usopp
Initially, Usopp was terrified at the sight of Chopper but after he learns that Chopper was Luffy's friend, he treats him better especially when the latter joins the crew. Due to his naïve nature, Chopper is a fateful listener to Usopp's lies, most of which he really believes, at least for a short time. Initially bonding with Usopp as one of the weaker members of the crew, Usopp advised him that "you must always still do what you can do for the crew". This includes never running away in certain circumstances, especially when the dreams of your friends aren't being taken seriously. He has taken this advice deeply to heart ever since. In fact, he felt his first validation as a pirate when he decided not to run from Skypiea Priest Gedatsu, and eventually defeated him. When Usopp left the crew, Chopper was one of the most affected crewmembers, and after Luffy beat Usopp in the duel for the Going Merry, Chopper wanted to go treat his injuries immediately but had to be forcibly stopped by Sanji, who ordered him not to stomp on Usopp's pride by healing him after his defeat (when he already had been given mercy by Luffy). Chopper still gave some medicine for Usopp to use but left him be. Chopper missed Usopp dearly despite Zoro telling him not to mention his name anymore and fell completely for Usopp's "Sogeking" disguise, even asking him for autograph. After Enies Lobby, when Usopp apologized and rejoined the crew, Chopper burst into happy tears of joy as his friend returned. Chopper, Usopp and Nami were most scared in Thriller Bark, but Chopper was willing to fight off zombies to save Usopp and both them united to protect Nami from Absalom and Lola.

After the timeskip, Chopper is still in awe of Usopp, as seen in Zou when he hugged Usopp after their reunion.

Roronoa Zoro
Chopper also seems to have a close relationship with Zoro, whom Chopper near idol worships because he is "so cool". Much like he does with Luffy and Usopp, they have a very close relationship. During the Davy Back Fight Arc, Chopper is separated from the crew due to the Straw Hats losing an event, and becomes distraught. Zoro yells at him to quit complaining, as being a pirate was his decision, and thus in this world no one will respect his tears. This strengthens Chopper's resolve as a pirate, and he becomes much less prone to crying and complaining, despite his child-like nature. Zoro taught Chopper that even though every crewmate has separate dreams, they still stick together as a crew and are stronger this way. One of his favorite things to do is to ride on Zoro's shoulders when they are traveling and often runs to him when he is scared. Zoro also seems more protective of Chopper than anyone else. It is seen that Zoro is the one to save him when he comically falls into any form of water when trying to escape Nami's wild mood swings (while Sanji has saved Luffy frequently in comparison), though Chopper still gets annoyed with Zoro whenever he takes off bandages from injuries he sustained from battles or is attempting to train before his injuries have fully healed. However he does irritate Zoro when Chopper clings to his face to avoid falling into water such as what happened at Water 7 during Aqua Laguna. Chopper is not afraid to argue or wrestle the swordsman, and hates it when Zoro shows lack of care for absent crewmembers.

After the timeskip, Chopper is more willingly to beat Zoro up for any stupid decision making but still strongly respects his skills as shown when he was awestruck by his vastly improved strength in the fight against Surume.

Nami
Nami is very fond of Chopper, and is the first of the crew to recognize him as a doctor. She respects his knowledge in medicine and cares for his safety as much as her own. Likewise, Chopper respects her ability to navigate; though he tends to be afraid of her obsessive love for money and violent nature towards the "idiots" of the crew so much so that he runs or puts up his Guard Point during these mood swings. The two share a relationship that is much like an older sister's and a younger brother's. Nami will hug onto Chopper's fur for warmth in cold situations or when she is scared. Nami and Chopper are very protective of each other, like when Franky first suggested killing Chopper to end his rampage in his Monster Form Nami threatened to kill him if he did so (though the two did come up with a better plan to save Chopper). In spite of this Nami did hold Chopper up as a shield from a charging Zoro who Nami thought Zoro was going to attack her on Punk Hazard, when in truth, Zoro was trying to protect them from Monet. Nami and Chopper also bonded in sadness over Sanji's exit in Zou and were the first to volunteer to go save him with Luffy.

When Absalom was stalking Nami, Chopper went out of his way to protect her. Nami also comforted Chopper when he was upset over Hogback's betrayal. Due to his innocence and lack of interest in human females, Nami lets Chopper (despite him being a male) see her naked in the bath and even invites him to join her.

Sanji
Sanji originally wanted to cook Chopper (along with Luffy who wanted to eat him raw) and jokingly wants him to join as "emergency food supply" in the Drum Island Arc but Sanji also listened with Nami to Chopper's past, learning that humans attacked him for looking like a monster so when Chopper asked Sanji what Luffy "was" Sanji replied with a smile: "He's a monster" showing the doctor that being different didn't mean you couldn't be accepted. Throughout the series Sanji continues to refer to him as "the emergency food supply" to tease him, but strongly considers Chopper a friend in fact due him being the youngest Sanji cares for him most out of all the males on board the crew. Chopper idolizes the cook for his raw fighting strength and is awed by Sanji's burning rage. Chopper will often hide behind Sanji's leg when Nami's angry or there is an enemy close by, leading to Sanji patting Chopper's head in comforting way and Chopper will sometimes take a ride on the cook's shoulders. Sanji has taught Chopper many lessons like when Robin was leaving the crew Sanji told the doctor that a real man forgives a woman's lies. Chopper was one of the first people to realize how life threatening Sanji's nosebleeds were, even begging the fish-men for blood donations. Chopper cried with joy when Sanji saved them from Doflamingo, was highly interested in Sanji's marriage to Pudding, and completely distraught (along with Nami) over Sanji leaving the crew even yelling at Zoro when the Swordsmen ridiculed Sanji.

Chopper was so anxious to see Sanji again he mistook Sanji's malicious brother Yonji for Sanji when he fist saw the Vinsmoke. Chopper like the rest of the crew was shocked when Sanji turned down Pudding.

Nico Robin
He shares a taste for reading with Robin who called him "Doctor-san" when she first joins the crew, which made him dance in joy. They also seem to have a genuine sense of respect for each other, possibly due to their pursuits in knowledge; ironically, he was originally rather intimidated of Robin upon finding out that she specializes in assassinations, fearing that she will one day assassinate him once his guard has been let down, but at the same time, was amused when she first displayed her Devil Fruit powers to entertain both him and Luffy, and eventually opened up to her. His fondness towards Robin is what compelled Chopper to use his Monster Point Form against Kumadori during his battle in the Judiciary Tower. In return, she treats Chopper not only an equal in terms of intellect but also with a motherly nature as she got him out of the clutches of Foxy's right hand woman.

Franky
Though he disliked Franky at first when they officially met at Enies Lobby, blaming him as the reason Usopp left the crew and for beating up the sniper (unaware their new friend Sogeking is Usopp) as well as stealing their treasure. When Chopper was fighting Kumadori he encountered Franky also fighting CP9 agent Fukuro, the Cyborg request that Chopper throw him some him some cola, Chopper was reluctant to do but threw Franky some bottles anyway. Chopper watched in amazement as the Cyborg's hairstyle and attitude changed until Franky yelled at him to stop messing around as he saw that Chopper was enjoying seeing him change with every drink saying, "He's the funniest thing ever". When Chopper went on a rampage in his Monster Point, Franky initially suggested killing him but at Nami's strong urging he changed his decision. Franky instead knocked Chopper into the ocean to deactivate his powers and quickly dived into the water to save him before he drowned. After the conflict, it appears any lingering animosity Chopper possessed towards Franky has ended as he was alright in letting him be a member of the crew.

After Franky's entry into the crew, Chopper is amazed by Franky's inventions (especially the Mini Merry II) and shows great respect for him. He is also in awe of Franky's robotic body, especially after the timeskip. Franky is very much a brother figure towards Chopper and the cyborg will let the doctor ride on his head when they are traveling.

Brook
When Chopper first met Brook, he was understandably terrified of him because he was a walking, and talking skeleton and argued with Usopp that would not accept him as a crewmate. But after hearing the story about Brook and Laboon, Chopper cried and even stated he was not afraid of skeletons anymore. After Brook's entry into the crew, Chopper and Brook get along very well despite Brook being the oldest Straw hat and Chopper being the youngest. It is shown Chopper loves the undead skeleton's music and will often dance to it.

After the time-skip, Chopper is not afraid to yell at the undead musician, making Brook scream in a panic, which is ironic considering he has more of a frightening appearance. Brook did get jealous of Chopper and Momonosuke getting special treatment from Nami and was reluctant to play songs when requested but hating to disappoint Chopper and Nami so he played for his friends anyway. When Jora attacked, Brook feigned allegiance towards her. Chopper was afraid that Brook betrayed them but was relieved when Brook saved them instead.

After Brook was captured by Charlotte Linlin in the Whole Cake Chateau, Chopper was of the few who took part in retrieving him and after doing so, he was amazed that Brook managed to gain copies of the Poneglyphs in Big Mom's possession.

Drum Island
Back on Drum Island, the people have come to accept his help in defeating Wapol, even though originally they were afraid of him.

Dalton
Dalton also has a sound view of Chopper, whom he views with the highest respect having saved the kingdom of Drum and was the one who saved his life six years ago by stopping an angry Chopper from fighting a hopeless battle against Wapol and his army to avenge Hiriluk's death, having recognized what he was trying to do. He keeps an eye out for Dr. Kureha's "son" and was the first to tell her when Chopper gained a bounty.

Sodom and Gomorrah
Sodom and Gomorrah have developed a special relationship with the doctor of the Straw Hat crew, since he was the only one who could understand what they were saying and could translate their wishes and feelings to the rest of their comrades. After the battle, Chopper was also the one to treat their serious wounds, for which they were grateful.

Torino Kingdom Citizens
After being "sent" to the Torino Kingdom, Chopper was very distressed as he was treated as a plaything by the birds and hounded by the natives as food. However, after Chopper managed to resolve the conflict between the natives and the birds, he was treated almost like a hero. After receiving Luffy's message he returned and the natives were glad to share their knowledge of herbs, medicines, and plants with Chopper, especially after he helped solve their conflict. The giant birds of Torino Kingdom were also happy to fly Chopper to the Grand Line whenever he wanted to.

Mink Tribe
Due to his group's efforts in saving the Mink Tribe after they were devastated by an attack from Jack, Chopper and his crew are considered as saviors to the minks. Therefore, they formed a harmonic relationship.

Milky
Chopper became highly infatuated with the female reindeer mink, Milky. When she rubbed against his cheek and called him "Doctor Chopper", Chopper fell over dazed in a very Sanji-like manner, complete with love hearts in his eyes, causing Usopp to wonder what had come over the usually platonic Chopper.

Carrot
Chopper became well acquainted with Carrot after she joined the 'Sanji Retrieval Team' to Whole Cake Island. They work well together as a team, having helped each other navigate Charlotte Brûlée's Mirro-World and successfully enacting their plan to defeat her. Carrot herself respects Chopper's strategic genius and affectionately refers to him as "Cho-niki" (a portmanteau of Chopper and "brother").

Wapol
One of Chopper's major enemies is Wapol, the spoiled king who insulted the death of Chopper's surrogate father, Dr. Hiriluk, among other things. With Luffy’s coming, Chopper not only managed to get revenge for his father but also with Luffy’s aid, they managed to prevent Hiriluk’s flag from being burnt.

Marines
He is wanted by the Marines, albeit with an extremely low bounty of only 100 belly due to being mistaken as a pet, and with only one of his transformations noted in the bounty poster.

Hogback
Chopper initially idolized Dr. Hogback solely based on his reputation as a doctor of legendary skills and outright and angrily stood up for him when Nami and Usopp spoke negatively about him based on the suspicious circumstances, despite barely knowing the man personally. However, after learning of his disregard for human life and that he uses his medical expertise only for fame and wealth while considering his patients as annoyances (as opposed to Chopper's philosophy of a doctor must cure any patient regardless of reward and circumstances), Chopper declared that he no longer considers him a doctor and even tried to smash his head when coming into conflict with him and the rest of Gekko Moriah's forces.

Caesar Clown
Despite not having had a personal encounter with Caesar Clown (until the end of the Punk Hazard Arc), Chopper has quickly grown to despise the mad scientist after discovering the cruel experiments he conducted on the children he kidnapped (similar in a way to Dr. Hogback). Despite this, after saving the children, Chopper's hatred of him seems to have lessened somewhat, willing to heal his wounds after his confrontation with Luffy, even stopping Sanji from kicking him in the face anymore while healing him (but he did give him permission to continue after he was done patching him up). Chopper has also shown admiration for Caesar's scientific expertise, if only momentarily, after believing he was the one who was originally responsible for creating SMILE's, even calling him a "genius" (which he enjoyed), but quickly dismisses him after founding out that Vegapunk was the one who really discovered it first. However, upon seeing Caesar's delight at how his Koro gas decimated the Mink Tribe, Chopper finally lost patience with him and beat him up personally, forcing him to make an antidote for the minks while Sanji threatened to destroy Caesar's disembodied heart.

The Herd
Chopper's biological family is a herd of reindeer, who abandoned him for being different. Initially estranged for being born with his blue nose, he is further abandoned after eating the Hito Hito no Mi, which gave him two "unreindeer-like" humanoid forms. He eventually found his path intertwined with them again during his days with Hiriluk when he was beaten up by them (where his left antler was broken). However, he was able to pass through them despite this and achieve his goal at the time.

Hiriluk
Hiriluk was Chopper's mentor who took him in and became his "father".They had a close relationship with each other, and had formed a deep bond despite their almost constant arguing with each other and Chopper had a hard time when he was informed of the disease Hiriluk is suffering from. He found Chopper one day while traveling home in a blizzard. At first Chopper tried to knock him away, but Hiriluk earned his trust by stripping naked in the cold, showing that he did not have any weapons or intention of hurting Chopper.

From then on, the two slowly formed a sort of father/son relationship, traveling (and in a way terrorizing) the island trying to cure patients and generally resulting in them having to literally run for their lives from angry patients or their associates. Despite his time spent with the superior Doctor Kureha, Chopper refers to Hiriluk as "the greatest doctor in the world." Hiriluk also gave Chopper his name, claiming his antlers looked like they could chop down trees.

Kureha
There is no such medicine that can cure all diseases. That's why we have doctors! You can't save people's lives with kindness alone. If you want to save them, you need medical skills and knowledge, otherwise you won't be able save anyone!! Chopper's adoptive mother and mentor in medical science. When she realizes that Hiriluk is dying, she agrees (reluctantly) to his last requests: to make his life's work come to fruition and to train Tony Tony Chopper in medicine. During the time since Hiriluk's death, she trains Chopper in medicine, claiming she taught Chopper "everything she knew", and was fairly impressed by the young reindeer's skill. She only once complimented Choppers skill in a filler episode, after Chopper cured her of a life threatening illness without any of Kureha's medical advice. Though neither family nor claiming to have adopted him, Dr. Kureha is his mentor. While she often hides her feelings towards him she considers him to be her son. She is very happy to know he is currently doing well.