The men known as The Wolf Pack are back in action. Bradley Cooper, Ed Helms, Zach Galifanakis and Ken Jeong all walked the red carpet of the Grauman's Chinese Theatre in Hollywood for the premiere of The Hangover Park II. The gang was also joined by the already-famous monkey, Crystal, from the film. In the movie, Phil, Stu, Alan and Doug go to Thailand for Stu's wedding. All Stu wants is a low key pre-wedding brunch. Knowing these guys, though, their night is everything but low key and quiet. The sequel to the 2009 film was directed by Todd Phillips. The movie will be released on May 26 by Warner Bros. The first move was the highest grossing R-Rated comedy of all time. As expected, the second part is also rated R. Below are photos from the premiere.