Wooper is a mostly blue, amphibious Pokémon that resembles an upright, armless axolotl. Wooper's head is large compared to its body, and it has small, round, black eyes. It has purple, branching gills on either side of its head; the males have more branches in its gills than the females. Wooper stands on two small, round feet, and it has a large, thick tail. On its belly are dark blue curved markings.