Dr. Freezegood

Dr. Freezegoods are snowmen wearing fezz hats, and are found in Super Mario World 2: Yoshi's Island. They ride ski lifts in World 5 and stand completely still unless they drop off on a slope. Yoshi cannot eat them, but he can step on their heads to rack up a few coins. They're harmless to touch, but they do hog up the ski lift platforms, which can become a bit of a nuisance as they are solid and can therefore push the Yoshis around. A certain Dr. Freezegood appeared in Tetris Attack, allied with Bumpty.

The more generic-looking Mr. Blizzard enemies of Super Mario 64 bare a resemblance to Dr. Freezegood, and several snowmen in Paper Mario do the same.

Trivia

 * Dr. Freezegood's name probably comes from Dr. Lovegood, or perhaps Dr. Feelgood.
 * Dr. Freezegood bears a passing resemblance to Mr. Blizzard and Snawful.