'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpet
Above, stars Bradley Cooper, Zach Galifianakis and Ed Helms pose with director Todd Phillips.
We're not sure if that extremely civilized photo was taken before or after Cooper horsed around on the red carpet with Diddy (left) and Mike Tyson.
Another one of the film's stars -- Crystal the monkey -- welcomes "Gossip Girl's" Kristen Bell:
Helms (shouldn't he have been home watching "The Office" season finale?) poses with castmate Ken Jeong:
Robert Downey Jr. and wife Susan:
A Crystal bonus shot: