From the Super Mario Wiki
A Snow Bunny is an item found in Paper Mario: The Thousand-Year Door. The Snow Bunny heals fifteen HP. However, the consumer of the item will be frozen after eating it if in a battle. It is made by letting Zess T. cook together a Golden Leaf and an Ice Storm.
The Snow Bunny returned in Super Paper Mario, this time requiring Mario to give Dyllis a Turtley Leaf instead of a Golden Leaf. Also, by then mixing the Snow Bunny with a Pink Apple, Mario could acquire the Berry Snow Bunny. In Super Paper Mario, the Snow Bunny froze all enemies currently on the screen.
Snow Bunnies in Mario Party 6
Snow Bunny-like creatures appear in the background on Snowflake Lake in Mario Party 6.
Names in other languages
||Conejo de Nieve