Yokozuna is a massive sumo-wrestling frog who was Tom's beloved companion before the legendary shipwright's execution. Grief-stricken, he developed an obsessive habit of throwing himself in front of the Sea Train, apparently driven by a desire to grow stronger so he'd never lose anyone close to him again.
He first caught the Straw Hats' attention when Zoro spotted him doing exactly that—swimming in an oddly human-like manner near Water 7. Luffy, thinking he looked delicious, briefly changed course to try catching him for a barbecue. Instead, Yokozuna ended up helping the crew anyway, charging the Rocket Man during their rush to Enies Lobby to rescue Franky and Robin.
At Enies Lobby itself, Yokozuna took on the job of barring government agents from the courthouse. He held his ground until the Jurors showed up, at which point the giants Oimo and Kaashii stepped in to help him defend the building. He made the journey back to Water 7 alongside Franky's crew, the Galley-La workers, and the giants.
These days he's moved on from his Sea Train routine—a recent side story showed him living peacefully in Water 7.
Franky taught him proper crawl-stroke swimming technique.
First Appearance: Chapter 322; Episode 228
Content compiled by AnimeList.moe from publicly available sources.
