Stars Monkey Around at 'The Hangover 2' Premiere

The stars of The Hangover Part II atteneded their Hollywood premiere at The Grauman's Chinese Theatre in Hollywood, Calif. yesterday and were joined by their favorite furry friend - Crystal the monkey.

Bradley Cooper, Ed Helms, Zach Galifanakis, Justin Bartha, Ken Jeong and Mike Tyson were all spiffed up while Crystal the monkey was all dolled up in a little pink dress.

Also at the premiere were engaged couple Dax Shepard and Kristen Bell and recently voted off Dancing With The Stars contestant, Romeo Miller. A very pregnant Alyssa Milano walked the red carpet as she proudly showed off her baby bump.

The Hangover Part II hits theaters May 26. Check out the hilarious trailer below!