Greninja is a Water/Dark-type Pokémon featured as a playable fighter in the 'Dairantou Smash Bros.' (Super Smash Bros.) series. Known as 'Satoshi Gekkouga' in Japanese, Greninja is famous for its speed, agility, and unique ninja-like fighting style. This Pokémon belongs to Ash Ketchum in the anime and is recognized for its powerful moves and transformations. In the Smash Bros. series, Greninja utilizes swift attacks and water-based moves, making it a popular choice for players who value agility and versatility in battles.