at the hidden village after you complete the save the village and a bunch of cats are hanging around all over there is a chicken (i know they are called cuccos but chicken is better) talk to him as a wolf to start a mini quest, the goal is to talk to all 20 Cats/Kittens then talk to him again. he then tells you that your prize, which is a piece of heart. will be at the front door of impa's house.