On Days 1 and 2 transform into Goron Link and blow up the rock on Milk Road using a Powder Keg (Alternatively, you can enter the ranch on Day 3 when the rock is destroyed by the miner). Go all the way to the Cucco Shack in the back. The Bird-Keeper, Grog, is sad because his freshly-hatched chicks won't turn into adults by the time the Moon crashes. Why not help make Grog's dream come true? But the Bermen's Mask on and march through the field. Make sure you go near every chick so that they follow you. When all the chicks are with you, they begin to transform into Cuccos! Continue to March until they all crow. Grog will be filled wih joy (although he doesn't show it). As a reward, you get the Bunny Hood.
The Bunny Hood allows Link to run twice as fast and jump farther.