Marc Klasfeld and Danny Lockwood hire the worst party entertainers imaginable in their zany promo for Katy Perry's Birthday.

Perry ditches her usual glam persona to impersonate five different characters including a clueless animal trainer, a scary clown, a dizzy princess and a fairly lewd geriatric dancer. Its all good, clean mayhem - coinfirming that of all the top pop divas, Katy is the one with the chops for comedy.