Robo-Mouse

Robo-Mouse is an undefeated enemy appearing in Wario Land 3 in The Stagnant Swamp, after entering the first door.

Robo-Mouse is, like its name implies a mouse-like robot with a tail, wheels to move and claws to destroy walls in its way.

When Robo-Mouse sees Wario, it'll chase him and try to catch him with his claws. If it does, it'll kick Wario out of the area.