Cat Viper Full Body

Master Cat Viper

Cat Viper (ネコマムシ, Nekomamushi), also known as Master Cat Viper (ネコマムシの旦那, Nekomamushi no Dan'na), is a feline mink and the guardian of the Whale Forest on Zou, dubbed the "Ruler of Night" (夜の王, Yoru no Ō) as he rules over the Mokomo Dukedom from 6:00 PM to 6:00 AM. He and Dogstorm serve as retainers for the Kozuki Family of Wano Country.

Alongside Dogstorm, he was also once a member of the Whitebeard Pirates and Roger Pirates, serving under Oden Kozuki. Pedro has claimed that he and Dogstorm must not be allowed to die because "the world is waiting for them".


—Cat Viper.

Appearance & BiographyEdit

Voice Actor: Not Known (English), Masaru Ikeda (Japanese), Not Known (Italian), Not Known (Spanish), Not Known (German), Not Known (Finnish), Not Known (Korean), Not Known (French), Not Known (Latin American Spanish)



Cat Viper is a large, yellow feline mink with sharp teeth, claws, and a very thick striped tail. He has wild, bushy blonde hair resembling a lion's mane running around his neck and down his back, and there is a scar running from the left side of his forehead down to his cheek. His outfit consists of a large robe decorated with circles, a haramaki around his waist, sandals, a light-colored shirt, and pants. In addition, he frequently smokes a kiseru.

Like all the retainers of the Kozuki Family, Cat Viper bears the family crest somewhere on his body.

While being tortured by Jack, he lost his left hand and part of his left forearm due to several members of the Beasts Pirates spearing them off.

  • Hair Color: Blonde
  • Fur Color: Yellow
  • Skin Color: Not Seen
  • Eye Color: Not Seen
  • Age: Not Known
  • Birthday: November 22
  • Height: Not Known
  • Weight: Not Known





Cat Viper takes great pride in his status as one of the two rulers of the Mokomo Dukedom alongside Dogstorm, having proclaimed the country to be his when the night comes during his first encounter with Jack.

Unlike his former friend Dogstorm, Cat Viper is aggressive and merciless; Dogstorm has described him as an "obstinate and stubborn imbecile", comparing him to Jack himself, and he is completely willing to damage the historical Mokomo Dukedom while fighting, referring to doing so as a "minor detail". Cat Viper can be stubborn even when not angry, as demonstrated when he kept ignoring Chopper Tony Tony's orders to recuperate in order to have fun. He does not like to be ordered around, having claimed that he went to bed of his own volition rather than on Chopper's orders while being treated by the doctor, and describes himself as a "freedom-loving man"; in spite of his bravado, however, he is afraid of needles.

Despite his stubborn and sometimes abrasive behavior, Cat Viper genuinely care for his friends and fellow minks; he took care of Bepo and the other Heart Pirates when they arrived on Zou and did not expect them to help him defend the Mokomo Dukedom against the Beasts Pirates, though he was impressed when they decided to do so anyway. Additionally, while being tortured by Jack and his men, Cat Viper convinced the Beasts Pirates to aim their spears at him instead of at his incapacitated fellow minks. He is also firmly loyal and possesses an incredibly strong will, having absolutely refused to reveal that Raizo was on Zou despite extensive torture at the hands of Jack even when he lost his arm, and was fully willing to risk the kingdom's destruction in order to protect his friend. His loyalty to his allies means that he will treat anyone who tries to harm them viciously, having claimed he will devour any intruders he finds.

Cat Viper has many feline behaviors that can sometimes get the better of him; he likes to lick his paws, play with balls and cat toys, and eat catnip. Unlike most cats, however, he loves taking baths. His favorite food is lasagne.

Like many others, Cat Viper has his own unique laugh: "Goronyanya". "Nya" is the Japanese onomatopoeia for a cat's meow, and "goro" may come from "gorogoro", the Japanese onomatopoeia for purring.







Abilities and PowersEdit

As the leader of the Whale Forest Guardians, Cat Viper has authority over the forest's inhabitants. During night time, he also becomes the main authority figure of the Mokomo Dukedom.

Cat Viper is equal in power to his daytime counterpart and former friend Dogstorm, causing all of their battles to end in stalemates; this was proven when he fought evenly against Jack, the right hand man of the Emperor Kaido with a 1,000,000,000 Berry bounty, before the latter poisoned him with Caesar Clown's Koro gas. Even while Cat Viper was recovering from severe injuries, Sanji confidently left the protection of his comrades from the Firetank Pirates to him, while Bege Capone felt wary of facing him and called him a monster.



Physical AbilitiesEdit

Cat Viper possesses extraordinary physical strength, demonstrated when he easily flipped Jack over and slammed him into the ground in his mammoth form, and is also extremely fast, having traveled from the Whale Forest to Kurau City in a matter of seconds. While all the other minks were immediately weakened and left unable to move by the Koro gas, Cat Viper retained much of his strength and almost tore apart the chains that bound him to his crucifix, demonstrating tremendous endurance. Like all minks, he can use Electro.

It is unknown how much the loss of his hand affects his overall combat abilities, but he managed to clash evenly with a one-legged Dogstorm.

Strength levelEdit





Cat Viper wields a staff resembling a jumonji yari with a fire-shaped blade on each end, which he can channel Electro through.





In the distant past, Cat Viper and Dogstorm were friends. As retainers of the Kozuki Family, they traveled the seas together with Oden Kozuki, which led to them sailing on the ships of both Whitebeard and Roger D. Gol. However, Cat Viper and Dogstorm never went to Raftel.

Some time later, after returning from the voyage barely alive, they had begun hating each other to the point that they began fighting whenever they were together, so they decided that Dogstorm would rule Zou during the day and Cat Viper would rule during the night.

When Bepo and the Heart Pirates arrived, Cat Viper took them under his care because, despite his status as a pirate, Bepo was a native of the island.

As night fell during Jack and the Beasts Pirates' invasion of Zou, Cat Viper quickly emerged from his domain and flipped Jack over. Cat Viper prepared to fight Jack, and was pleased to see the Heart Pirates assisting the Guardians in the battle. He fought Jack for five straight nights, switching out with Dogstorm once 6:00 AM arrived. Finally, Jack lost patience and used the Koro gas on the minks. He then crucified Cat Viper, Dogstorm, and other strong minks and tortured them for Raizo's whereabouts. However, the minks unwaveringly refused to give the ninja's location, and Cat Viper nearly broke free from his chains, leading Jack and his men to sever his arm.

One day later, Jack left Zou and the Straw Hat Pirates led by Sanji arrived. After chasing away the remaining pirates and neutralizing Koro, the pirates tended to Cat Viper and the wounded minks.

Several days later, while Bege Capone was dealing with Sanji inside his body, Cat Viper confronted Bege after finding an injured Pekoms, which prompted Sanji to throw his crewmates out of Bege's body. Not wanting to fight Cat Viper despite his visible injuries, Bege fled with Sanji and Caesar. Realizing that the remaining Straw Hats wanted the minks present to forget about what just happened, Cat Viper told Wanda and Carrot to keep quiet about the incident and decided to look after Pekoms.


Yonko SagaEdit

Zou ArcEdit







See alsoEdit

External linksEdit

Notes & TriviaEdit

  • "Neko Mamushi", although not written in kanji, means "Cat Viper", which the VIZ translation used as a title, under the impression that his real name had not yet been revealed. The title of "Master" was added on later.
    • Brook's voice actor, Chō, made-up a song about "going off to meet the Cat Viper." It impressed Oda enough that he decided to integrate Cat Viper into the manga, as well as the song itself.
  • His relationship with Dogstorm seems to be based on the idea that a cat and a dog cannot get along well with each other, evidenced by their rocky relationship.
  • His design is similar to the Cheshire Cat from Lewis Carroll's Alice's Adventures in Wonderland.
  • His love of lasagna is similar to the comic strip cat, Garfield, created by Jim Davis.