hangover cast gi 'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpetOn Thursday (May 19), the cast of “The Hangover Part II” and several of the film’s celebrity supporters gathered at Hollywood’s Grauman’s Chinese Theater to attend the movie’s premiere. The movie opens in theaters nationwide on May 26.

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.

hangover bradley gi 'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpetAnother one of the film’s stars — Crystal the monkey — welcomes “Gossip Girl’s” Kristen Bell:

hangover crystal kristen gi 'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpetHelms (shouldn’t he have been home watching “The Office” season finale?) poses with castmate Ken Jeong:

hangover ed ken gi 'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpetRobert Downey Jr. and wife Susan:

hangover rdj gi 'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpetA Crystal bonus shot:

hangover crystal gi 'The Hangover Part II' premiere: Bradley Cooper, Ed Helms, Kristen Bell, Mike Tyson walk the red carpet