You can get a piece of a heart by talking to all the cats by the old lady's house (you have to be able to turn into a wolf at will). First talk to the cucco and he'll tell you what to do. Then talk to a cat and it'll say something and tell you how many you have talked to. After talking to a cat, turn into human and pick up the cat, and go where the cucco is and drop the cat (that way the cats can't run away and accidently count them again). After talking to all the cats talk to the cucco again and he'll tell you where the prize is.