Buizel

Buizel (ブイゼル, Buizeru, Buoysel in original Japanese language versions) is classified as the sea weasel Pokémon. It is a water type.

Anime
Dawn caught a Buizel, trained him for a while, and then traded him to Ash for his Aipom. Buizel is voiced by Rob Paulsen.

Pokemon description
Buizel floats in water by inflating the floatation ring around its neck and deflates the ring when it needs to dive. It swims by corkscrewing its two tails, which help swimand keep on top of the water