Snowman Wario

Snowman Wario, also known as Snow Wario  , is one of Wario's many reactions in the Wario Land series of games. It is triggered by having a snowdrift fall on Wario's head. He is then covered in snow, reducing his walking speed and jumping height, but allowing him to defeat enemies when he touches them. Also, in a similar manner to rolling, if he steps on a slope, he will become an uncontrollable rolling snowball that is able to break Snowman Blocks. When he hits a wall in this state, he will return to normal.

Wario Land 4

 * Nintendo 3DS Ambassador Program digital manual bio: Press to move and  to jump. Press  on a slope to roll.