The little bird pops out like a in a real clock. There's also a jiggleboned pine cone. Replaces the Pyro's Gibus. The hat is very low poly, it shouldn't make a difference in the number of fps.
SADLY THE HAT DOESN'T MAKE ANY SOUNDS.
From what I know it's impossible to add sounds to hats. ( A note - I know how to, I managed to get the sounds working, but only when the hat is viewed alone, as in not on the players head) I'd like to be proven otherwise though.