Keaton

Keatons are yellow foxes with 3 tails that appears in Majora's Mask. To get them to appear, you need Keaton's Mask and to cut some Moving Grass for example the grass in North Clocktown. You must have Keaton's Mask on when you cut the grass! The Keaton will then appear and ask you some questions about things in Majora's Mask. If you answer them all right, you will get a Piece of Heart. Keaton's charecteristics are derived from the mythological japanese fox creature, kitsune.

Keatons are also enemies in The Minish Cap. Quote from The Legend of Zelda: The Minish Cap Keaton figurine:

"Appears in various areas. This thieving fox preys upon travelers and merchants. He may not be strong, but he will attack very quickly, so be careful."