Marill

Marill is a small, blue, bipedal semi-aquatic rodent Pokémon. It has a nearly spherical shape with a white belly and it has round ears with red insides. These sensitive ears can detect distant sounds. Marill's arms and feet are short and possess no visible digits. There is a blue, bubble-like ball at the tip of its zigzagging black tail. The tail is flexible and configured to stretch, and the ball is full of oil that acts as a buoy to help keep Marill afloat. The ball at the tip of its tail can glow when Marill attacks. In the Pokémon the Series: Ruby and Sapphire episode Abandon Ship! (AG032), Marill was shown to be able to bounce on its tail. In the TCG, Marill is shown to rapidly spin its tail, seemingly readying for an attack.

Marill is able to swim in strong water currents without being slowed down by the water's resistance, due to its water-repellent fur. Marill feeds on aquatic plants in addition to fishing for food. When it dives, its tail can be seen bobbing on the water's surface. It will anchor its tail around a tree when fishing at the edge of a fast-moving stream. Marill never gets cold after swimming in cold water, due to its water-repellent fur drying up quickly the moment it leaves the water. It lives on the water's edge.

Evolution Marill evolves from Azurill and evolves into Azumarill.

(Source: Bulbapedia)