Wadatsumi

"Onyudo" Wadatsumi (大入道ワダツミ) is a giant tiger blowfish fishman and a member of the Flying Pirates under captain Vander Decken IX.

Appearance
Wadatsumi is an enormous fishman, equal in size to the head of the kraken, Surume. He is large enough to make the giant-sized Shirahoshi and Megalo look human-sized and a regular shark. His round head and chest are quite big in comparison to his arms and legs. His hands are webbed. He has a big, round face, with a large mouth full of massive, round teeth quite distant from one another, and child-like eyes. He has some stubble on his chin and dark hair surrounding his head, taking the shape of a protrusion pointing upward at the top, which also covers a part of his shoulders. His whole body is also quite hairy.

He apparently wears a pair of extremely loose pants paired with a dark indument tied around his waist; and some sort of boot-like footwear.

His overall shape, size, and eyes strongly resemble that of Sanjuan Wolf's. Due to his appearance, Wadatsumi was incorrectly called an Umibozu by Usopp. Members of the New Fishman Pirates also refer him as such.

Personality
He is loyal and obedient, following Decken's every command without question. Despite his huge size, his personality appears to be childlike. Believing Decken has abandoned him, Wadatsumi cried and complained, but recovered when he was deceived into thinking he misheard, showing that Wadatsumi is naive and gullible.

Abilities and Powers
Due to his large size, and the fact that he is a fishman, he is extremely powerful. He shows his strength by hurting Ankoro, an angler fish several times the size of the Thousand Sunny, with a single punch, even though the punch was only intended to prevent the fish from eating the Straw Hat Pirates, and not to harm him. Also, living in the depths of the Grand Line, he is capable of breathing underwater as well as surviving the crushing pressure of 10,000 meters below sea level. Being a tiger blowfish fishman, he's also capable of inflating himself retaining air in his lungs, thus growing to double his enormous size.

After taking an Energy Steroid, his great strength increases further by being able to defeat Surume with one blow. He also has high stamina, taking powerful strikes from Jinbe and Sanji respectively and only slightly complaining about the pain.

Attacks

 * Mega Nyudo (メガ入道): Wadatsumi inhales a large amount of air, and expands his stomach to enormous proportions, crushing anything in his vicinity. If needed, he can expand even more, furthering his size. However, he must talk fast to prevent the air from leaking out. This was first seen used against Sanji, though he indiscriminately crushed his New Fishman Pirates allies.

Fishman Island Arc
While the Straw Hats (minus Luffy, Zoro, and Sanji) were sailing through the underworld of the sea, Wadatsumi suddenly appeared from the rocks beneath the sea. He beats an angler fish with one blow to prevent it from eating the Thousand Sunny because the captain of the Flying Dutchman, Vander Decken IX, wants their treasure. On Vander Decken's orders, Wadatsumi attempts to punch Thousand Sunny, but the kraken (which had been tamed by Luffy, Zoro, and Sanji) intervenes and knocks out Wadatsumi.

When the volcano erupts, Vander Decken orders Wadatsumi and Ankoro to pull the ship away from the magma. As the water temperature rose, he and the Flying Dutchman were thrown forward.

He is later seen walking on the sea floor pulling the Flying Dutchman. Vander Decken IX asks how many years it has been that the Mermaid Princess has not replied to his letters. Wadatsumi answers that it has been ten years and the princess still has not replied, enraging Decken. He is then seen in Noah in the Fishman District where Vander Decken IX and Hody Jones form an alliance.

After Luffy takes down Decken at Coral Hill, Decken calls out to Wadatsumi to prevent Princess Shirahoshi from escaping. Luffy beats him back with a Jet Pistol, breaking off one of his teeth.

Wadatsumi is then seen back at the Fishman District and later running away, deeply shocked that his captain "threw" Noah toward Shirahoshi.

When Noah and the Flying Pirates arrive to Gyoncorde Plaza, Wadatsumi falls into the plaza and begs for his life to Vander Decken IX. Decken replies that he cannot stop the boat anymore and that he would become a necessary sacrifice for the end of Fishman Island. Fortunatley, the boat goes after Shirahoshi, who had just left Fishman Island to sacrifice herself.

Wadatsumi then gets beaten up by Surume. Saddened by Decken's betrayal, the giant has no will to fight back. Zeo talks Wadatsumi into fighting and gives him an Energy Steroid. Overpowered, Wadatsumi defeats Surume. He then tries to attack Jinbe, but he manages to deflect his attack, causing Wadatsumi to fall to the ground. Sanji then kicks him in the head, forcing the giant to stand up. Wadatsumi then fights against Jinbe and Sanji. Regardless of his size, Wadatsumi feels pain from their attacks.

Having a difficult time, Wadatsumi starts inflating himself, growing to a size that doubles his normal one. Sanji isn't at all afraid of Wadatsumi's new form and starts mocking him, telling him that Surume is still bigger than him. Wadatsumi falls for it and sucks even more air, keeping on growing and crushing many Fishmen Pirates in the process.

Major Battles

 * Wadatsumi vs. Surume
 * Wadatsumi vs. Monkey D. Luffy
 * Wadatsumi vs. Surume (Gyoncorde Plaza)
 * Wadatsumi vs. Sanji and Jinbe

Translation and Dub Issues
"Onyudo" (大入道), Wadatsumi's nickname, literally means "large, bald-headed monster" or "giant". "Umibōzu", which is what Usopp incorrectly refers Wadatsumi as, means "sea bonze", a Japanese mythological spirit. Wadatsumi's name itself is derived from "Watatsumi", the name of the Japanese sea god and dragon of Shinto religion.

Trivia

 * He is the largest fishman to date and the only one so far to have no obvious fishman appearance to him, aside from a dorsal fin and webbed hands.