Nidoking is a large purple Pokémon with a very large horn and large ears. It has a large bulky tail and it has one toed feet and three fingered hands.
Its abilities are Poison Point which may poison the foe 30% of the time when your Pokémon attacks it with a Physical kind of move. It can also have the ability Rivalry, which increases Nidoking's Attack stat by 50% when fighting against Pokémon of the same gender, but halves it when fighting against Pokémon of the Opposite Gender. In Pokémon Black and White, Nidoking has an additional Special Ability, through the Dream World; Sheer Force. This ability states that Moves with a secondary effect (Status, Lowering opponent's stats) are increased in power by 33% but lose their secondary effect (i.e. Flamethrower would not cause burn).
In the anime
Gary has a Nidoking in the anime. Aside that, Nidoking makes many other appearances in the anime.
Nidoking is the evolved form of Nidorino by use of a Moon Stone. Nidoking is the final evolution of Nidoran♂.