Yokozuna is a large frog like a sumo wrestler, a legendary shipbuilder friend, fishman Tom. Even though it's a frog, he's actually good at freestyle swimming. He is also friends with Franky.
Appearance
Yokozuna is a giant frog with yellow-brown skin and thick black hair to the back that blends with a distinctive sideburn style. He has a scar on his stomach, due to being injured fighting a sea train. He also has pointed teeth and wears typical red wrestling pants.
Personality
He is very loyal to Franky who has been friends with him since childhood. Then he tried to train himself to be stronger in order to protect the people he loved.
Relationship
Yokozuna is good friends with Tom, and also Kokoro, Iceburg and Franky. In Water 7, he lived in Tom's house and helped during the construction of the sea train. Yokozuna has the habit of challenging Tom's Puffing train after the incident that happened to Tom eight years ago. He also tried to block Rocketman because he thought Kokoro would be kidnapped. He then went to Enies Lobby to free Franky.
Ability
He is a strong swimmer. Even though it was a frog, Yokozuna actually swam freestyle thanks to Franky's hard training. He was also very strong, capable of derailing sea trains which caused him to have scars on his face, arms and stomach during years of fighting. During his time at Enies Lobby, he easily caught an eleven jurymen iron ball attack which was even able to defeat King Bull before.
History
Past
Yokozuna is Tom's best friend from Gyojin Island to move to Water 7. In Water 7, he lives in Tom's house with Kokoro, Iceburg and Franky. Yokozuna helped during the construction of the sea train until it was finished. Seen he jumped happily at the opening of Tom's Puffing.
When Tom will be taken to Enies Lobby, he is seen with Franky trying to block the departure of the sea train.
Water 7
Yokozuna was first seen swimming in the ocean in front of the Going Merry ship. The Straw Hat crew took the initiative to chase him but their ship was trapped by the sea railroad. He then tried to block the pace of Tom's Puffing train but was hit and bounced away.
He reappeared while trying to stop the Rocketman train heading to Enies Lobby. Kokoro's grandmother informs them that they are struggling to save Franky. He then participated in the group for the same purpose.
Enies Lobby
In Enies Lobby, Yokozuna helped prevent the Government agent's business from entering the courthouse. He stopped a large iron ball attack from the Jurymen. After being exhausted by all the attacks, the giant Oimo and Kashi came to help decide to take care of the courthouse and commented on acknowledging his greatness. After the straw hat crew fought CP9, he and his entourage were then defeated by the Navy. During a panic during the Buster Call attack, he and his entourage managed to escape and Yokozuna then boarded the Tom Puffing train with the Franky Family, the Galley-La foreman and the giant returned to Water 7.
Post Enies Lobby
After the Enies Lobby incident, Yokozuna was seen following Kokoro's grandmother, Chimney and Gonbe met a straw hat crew at the Galley-La headquarters. He was also seen helping Franky while making the Thousand Sunny and also when Franky joined the straw hat crew and went sailing.
Where are they now?
He is featured in the Cover Story series, no longer challenging sea trains.
From Ship Decks Around the World
Yokozuna was seen again on the cover of the story swimming with Kokoro enjoying their vacation.
Source : WIKIA ONE PIECE