Oshawott is a bipedal sea otter-like Pokémon, primarily light blue, dark blue, and white in coloration. Oshawott has a rounded, spherical white head, with small, triangular dark-blue ears to the sides. Oshawott's eyes are large, dark, and ovoid in shape; its dark-orange nose is shaped like an oval on its side. Oshawott also possesses speckles to the sides of its face, most likely meant to be a stylistic implication of short whiskers in the common manner of cartoon canines, and light blue bubble-esque features composing a "collar" around its neck. Oshawott's torso is light blue, and decorated with a pale yellow seashell feature in the center. Made out of keratin, this appendage, called a "scalchop", can be removed and used in various ways; mainly, as a weapon. Its small, digit-less and somewhat rounded arms are white in coloration, with its feet—having, unlike its forearms, discernible digits—colored dark blue. Oshawott also possesses a slightly plank-shaped dark blue tail and a pair of fangs unseen until it opens its mouth.

Ash's Oshawott
Ash's Oshawott first appears in In The Shadow of Zekrom!, under the ownership of Professor Juniper. He begins to admire Ash and decides to leave the lab and follow him wherever he goes. He then saves Ash and Iris from Team Rocket in Enter Iris and Axew! and reappears again in A Sandile Gusher of Change! where he officially joins Ash's party.