Momoo is a giant sea cow from the Grand Line, and the first Sea Beast seen in the series. He is classified as a Type A creature, “Big Friendly”.

Originally, he was utilized by the Arlong Pirates as a method of intimidation towards the residents of the Conomi Islands. After Arlong’s defeat, he was captured and employed as a draft animal by the Caribou Pirates.


Momoo is a giant sea cow with a seal-like structure, with a height of 36 meters (118’1″ feet) and weighing 16 tons (32,000 lbs). Despite having fish-like scales covering his body from his neck to his stomach, Momoo is classified as a mammal Sea Beast. These scales are actually his hardened skin, protecting his vital organs from external attacks as an armor.

He has a big, round nose with a gold nose ring, cow-esque face, horns, and green spots throughout his body. Besides helping him swim, his fins contain retractable bones sharp enough to act as claws.


Like most pirate pets, Momoo is very simpleminded, and spends most of his waking time focused on either food or obeying those he recognizes as superiors. As a carnivore of great size and strength, he has no qualms about eating any humans who approach him. However, he is easily intimidated by those he cannot overpower, and developed a severe phobia of the Straw Hat Pirates in particular after receiving multiple beatings from them, particularly Luffy and Sanji.

His behavior has not changed even after two years. After seeing the Straw Hats again during the journey to Fish-Man Island, he quickly fled in terror, but the Caribou Pirates easily forced him to turn back by giving him a lump on the head.

Abilities and Powers

Momoo is strong enough to destroy an entire village, as seen with Gosa Village. Momoo (as other sea cows) also has the strength to overturn ships while searching for food. He has a well-developed sense of smell, allowing him to lurk on the bottom of the sea and emerge at once to attack his target without giving them time to react.

Due to his gigantic fins, he can swim as fast as 70 km/h (43,5 mps). The hardened skin on his body serve as an armor, protecting him from external attacks. Momoo can also swallow his prey whole. His four stomachs (just as a normal cow has) are full of various bacteria and parasites that actively digest whatever he eats. Thus, Momoo won’t suffer any damage even if he eats a highly poisonous animal.



Momoo was allegedly found somewhere in the Grand Line by Arlong and his crew, though the exact circumstances remain unknown. During the Arlong Pirates’ reign over the Conomi Islands, Momoo was housed in a small underwater cave near Arlong Park, with Hatchan—who could summon him with a loud, trumpet-like call—serving as his main caretaker.

While normally left to his own devices, Momoo was occasionally called to act as an extra enforcer for the Arlong Pirates. Notably, he participated in their attack on Gosa Village, leaving it completely leveled and crisscrossed with a number of deep furrows.

East Blue Saga

Arlong Park Arc

Several weeks after the attack on Gosa, Momoo encountered Monkey D. Luffy, Sanji, and Yosaku, having followed the smell of cooking-smoke to their ship. His sudden appearance panicked Yosaku, but only annoyed Luffy, who immediately punched him for imposing on their lunch. Subsequently, Sanji took pity on Momoo’s hunger and willingly surrendered some of their food, but delivered an even harsher beating when Momoo tried to eat him too. Before he could escape, Momoo was harnessed to their ship and forced to tow them to Arlong Park.

Although he made good time overall, Momoo succumbed to exhaustion during the last part of the journey, and veered off toward Cocoyasi Village instead. Before he could be redirected, Momoo crashed headfirst into the coastline, knocking himself unconscious and violently (albeit non-fatally) flinging the Straw Hats’ ship into the woods outside Cocoyasi.

Later in the day, when the Straw Hats launched an all-out attack on Arlong Park, Hatchan summoned Momoo to fight for the Arlong Pirates. Upon seeing Luffy and Sanji, the still-injured Momoo immediately tried to flee, but was stopped by Arlong, who overrode his fear through sheer force of personality and forced him to attack. This attack was in vain, as Luffy easily overpowered Momoo again and spun him around mercilessly, using him to bludgeon most of Arlong’s forces before tossing him clear to the other side of Arlong Park.

Momoo made no further appearances for the rest of the fight, and was apparently forgotten by both the Straw Hats and his own crew; it is unknown what reaction, if any, he had to Arlong’s defeat.

Fish-Man Island Saga

Fish-Man Island Arc

Some time after the fall of Arlong Park, Momoo wandered away from the East Blue and into the waters near the Sabaody Archipelago, where he was captured by the Caribou Pirates. They used him as a means of advanced sea navigation. By putting a collar around his neck, they could hook him to the front of the ship, allowing him to pull them.

After moving the Caribou Pirates’ ship close to the Thousand Sunny, Momoo recognized Nami, Sanji, and Luffy. Frightened, he swam away, pulling the ship with him and leaving Caribou alone on the Thousand Sunny with the Straw Hat Pirates.

Momoo later returned at full speed and pulling Caribou’s ship with another lump on his head. When the Kraken destroyed the ship, Momoo was freed from the Caribou Pirates’ control and swam away.

Translation and Dub Issues

His name is an obvious reference to the “mooing” (モー, ?) sound made by cows, though it should be noted that Japanese pronounces this onomatopoeia with a “long” o-sound, rather than the “short” o used in English. Thus, the Japanese anime pronounces his name “Mohm” (indeed, the katakana used to spell his name are identical to those used to render the English name Maugham), while both the 4Kids- and Funimation-dubbed anime pronounce it “Moo-moo”.


Video Games

Playable Appearances

  • One Piece Bon! Bon! Journey!!
  • One Piece Treasure Cruise

Enemy Appearances

  • One Piece: Become the Pirate King!
  • Aim! The King of Berry

Non-Playable Appearances

  • One Piece: Grand Battle! Rush!
  • One Piece (Game Boy Advance)
  • One Piece: Grand Adventure
  • One Piece: Gigant Battle! 2 New World
  • One Piece: Dance Battle
  • One Piece: Pirate Warriors 3


  • While Momoo resembles a Sea King, he is actually just a giant sea-dwelling mammal.
  • Momoo’s favorite foods are roasted pig and shark.


  1. 1.0 1.1 One Piece Manga and Anime — Vol. 9 Chapter 73 (p. 3) and Episode 33, Mohmoo makes his debut shadowed as Hatchan calls for him.
  2. 2.0 2.1 2.2 One Piece Manga and Anime — Vol. 9 Chapter 73 (p. 6) and Episode 32, Momoo is formally introduced.
  3. One Piece Blue Deep: Characters World (p. 179), Momoo’s birthday is revealed.
  4. One Piece Magazine Vol.1
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Vivre Card – One Piece Visual Dictionary (Card #0101), Information about Momoo is revealed and his name is romanized.
  6. 6.0 6.1 6.2 One Piece Manga and Anime — Vol. 8 Chapter 70 (p. 15-16) and Episode 32.
  7. One Piece Manga and Anime — Vol. 9 Chapter 73 (p. 7) and Episode 32, Yosaku reveals Momoo’s origin.
  8. One Piece Blue: Grand Data File (p. 88-89), classification of animals by dangerousness.
  9. One Piece Magazine Vol.1
  10. One Piece Magazine Vol.1
  11. One Piece Manga and Anime — Vol. 10 Chapter 82 (p. 10-12) and Episode 38, Momoo shows his cowardice as he sees Luffy and Sanji, and then Arlong.
  12. 12.0 12.1 One Piece Manga and Anime — Vol. 62 Chapter 604 (p. 3-8, 10) and Episodes 523–524, Momoo returns as the Caribou Pirates’ advanced sea navigation.
  13. 13.0 13.1 One Piece Manga and Anime — Vol. 62 Chapter 605 (p. 4-5) and Episode 524.
  14. One Piece Magazine Vol.1
  15. One Piece Magazine Vol.1
  16. One Piece Manga and Anime — Vol. 9 Chapter 73 and Episode 33, Momoo is beaten by both Luffy and Sanji, then harnessed to their ship.
  17. One Piece Manga and Anime — Vol. 9 Chapter 74 (p. 19) and Episode 33, Momoo veers off-course.
  18. One Piece Manga and Anime — Vol. 9 Chapter 75 (p. 2-3) and Episode 33, Momoo gives Luffy, Sanji, and Yosaku a crash landing.
  19. One Piece Manga and Anime — Vol. 10 Chapter 82 and Episode 38, Forced to face the Straw Hats again, Momoo is quickly beaten by Luffy’s Gomu Gomu no Kazaguruma.
  20. One Piece Manga and Anime — Vol. 10 Chapter 83 (p. 2) and Episode 38, Momoo floats beyond Arlong Park’s front gate, unconscious, while the Cocoyasi villagers stand astonished at his defeat.
  21. One Piece Manga and Anime — Vol. 62 Chapter 604 (p. 10) and Episode 524.
  22. One Piece Manga and Anime — Vol. 61 Chapter 603 (p. 17) and Episode 523, Momoo tows the Caribou Pirates.
  23. See Ja.Wiki’s article on the writer W. Somerset Maugham.
  24. SBS One Piece Manga — Vol. 17 (p. 66), Momoo is confirmed not to be a Sea King.

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