Kelly Osbourne, Hilary Swank, Wilmer Valderrama, Blake Griffin
and – again, believe it or not – Tommy Chong
all make blink-and-you'll-miss-it appearances, but credit for the best guest has to go to Chelsea Handler
in her role as "irresponsible raver mom" with a crying baby in tow. (Axl Jack
, is that you?!) But there are even more famous faces where those came from – can you spot all the stars in Fergie's video? Watch below.