Marshtomp is an amphibious, bipedal Pokémon. Its body is primarily light blue with a lighter shade of blue for its underside and an orange belly. Marshtomp's head has an angular blackfin, orange eyes, and orange gills on the ends of both cheeks. It has long arms with three-fingered hands. Its feet have three small toes, and it has two black fins for tails.

This Pokémon has a thin, sticky film enveloping its body that enables it to live on land. This development came from living on muddy ground where there is poor footing. Despite this, Marshtomp is at its best when in this environment. Its body weakens if its skin dries out, so it plays in the mud on beaches when the tide is low to replenish fluids. It is capable of moving faster through mud than water. With its sturdy legs, it has a good footing in mud that allows it to overwhelm struggling opponents. Marshtomp lives in swamps and other wetlands.

In Generation III, Muddy Water was its signature move.

Marshtomp evolves from and evolves into .

(Source: Bulbapedia)