The Bunny Hood is an item from The Legend of Zelda series, mainly appearing in Majora's Mask. Unlike Ocarina of Time, the Bunny Hood in Majora's Mask gives you the power to run extremely fast.
Granted your trusted horse Epona was a much faster ride across the land of Termina, but in smaller areas it was a relief. Came in hand during some battles as well. Pretty easy to dodge attacks with it on.
I'm also glad it's powers make a cameo in the Super Smash Bros. series. Any character can wear the bunny ears, and get the top speed.