‘The Hangover Part II’ premiere

From left, cast members Bradley Cooper, Zach Galifianakis and Ed Helms pose with Todd Phillips, director and co-writer of the film at the Hollywood premiere of “The Hangover Part II” at Grauman’s Chinese Theatre. In the sequel to the 2009 hit, Justin Bartha, Cooper and Galifiankis head to Thailand to celebrate Helms’ bachelor party. The revelry comes to a head when the men lose Helms’ future brother-in-law. (Chris Pizzello / Associated Press)

Feb. 28, 2013 9:10 PM PT

Ed Helms plays Stu the dentist in the film. Stu goes to Thailand with his buddies for his bachelor party but when his fiance’s younger brother tags along, he gets lost in the ensuing debauchery, which forces them to find him in the mystery-comedy. (Chris Pizzello / Associated Press)

Bradley Cooper reprises his role as Phil Wenneck, the ringleader of the revelers in “The Hangover Part II” who delivers the news to his friend’s fiance that something went amiss during the bachelor party in Thailand. (Chris Pizzello / Associated Press)

Justin Bartha, the missing bachelor from the original “Hangover” film, returns with a bit more screen time (since he isn’t the one who’s lost) in the sequel. (Jason Merritt / Getty Images)

Ken Jeong poses with his wife Tran at Grauman’s Chinese Theatre. Jeong returns in the sequel, reprising his role as the flamboyant Mr. Chow, who unsuspectingly joins the bachelor party in Thailand. (Chris Pizzello / Associated Press)

Crystal the Capuchin monkey was the first to walk down the black carpet with her trainer at the premiere. Crystal replaces the white tiger from the first film that wreaks havoc on the film stars. (Chris Pizzello / Associated Press)

“The Hangover Part II” star Bradley Cooper poses with fans outside Grauman’s Chinese Theatre in Hollywood. (Chris Pizzello / Associated Press)

Boxer Mike Tyson reprises his cameo in “The Hangover Part II.” His iconic face tattoo makes an appearance on Stu Price’s face in the film. (Chris Pizzello / Associated Press)

“Sucker Punch” star Jamie Chung plays Stu Price’s fiance Lauren whose conservative family is shocked to learn that Stu had been married before -- to a stripper in Las Vegas. (Chris Pizzello / Associated Press)

“Sherlock Holmes” star Robert Downey Jr. walks the black carpet with his wife Susan. Downey starred alongside Galifianakis in the comedy “Due Date,” which was also directed by Todd Phillips. (Chris Pizzello / Associated Press)

Cast member Yasmin Lee plays a character named Kimmy in the film. (Paul Buck / EPA)

Mason Lee plays Teddy, the bride’s younger brother who goes missing in the film. (Paul Buck / EPA)

Cast member Sasha Barrese plays Tracy Garner, the wife of Justin Bartha’s Doug in the film. (Paul Buck / EPA)

Cast member Zach Galifianakais, left, shares a laugh with fellow film stars Justin Bartha, Ed Helms and Ken Jeong. (Chris Pizzello / Associated Press)

Cast members Ed Helms and Ken Jeong pose with Crystal the Capuchin monkey that tags along with the bachelors in the film. (Chris Pizzello / Associated Press)

Cast members Justin Bartha and Mike Tyson joke on the red carpet. (Chris Pizzello / Associated Press)

Recording artist and former “American Idol” contestant Jordin Sparks. (Jason Merritt / Getty Images)

“Chuck” actress Yvonne Strahovski will star in the comedy “My Mother’s Curse” with Seth Rogen in 2012. (Jason Merritt / Getty Images)

“Scream 4” star Kristen Bell and boyfriend Dax Shepherd of NBC’s “Parenthood.” (Alberto E. Rodriguez / Getty Images)

“Iron Man 2” star Robert Downey Jr. greets Bradley Cooper at the premiere. (Chris Pizzello / Associated Press)

“Parenthood” actor and funnyman Dax Shepherd smooches a poster of “Hangover” star Bradley Cooper. (Jason Merritt / Getty Images)

Actor Mike Epps played “Black Doug,” the person the guys thought was the their friend Doug (Justin Bartha) in the original summer blockbuster. (Paul Buck / EPA)

“Gossip Girl” narrator Kristen Bell poses for the cameras at the premiere. (Chris Pizzello / Associated Press)

“The Hangover Part II” director Todd Phillips walks the red carpet for the sequel of his 2009 hit. (Paul Buck / EPA)

Kristen Bell poses with Crystal the monkey. (Chris Pizzello / Associated Press)

“America’s Top Model” creative director Jay Manuel. (Jason Merritt / Getty Images)

“Harry Potter” franchise bad boy, er wizard, Tom Felton. (Jason Merritt / Getty Images)

“Extra” correspondent Terri Seymour. (Jason Merritt / Getty Images)

“Hall Pass” actress Alyssa Milano shows off her baby bump at the premiere. (Paul Buck / EPA)

“The Office” funnyman Rainn Wilson, who co-stars with Ed Helms in the NBC sitcom. (Paul Buck / EPA)

Music producer and mogul Sean “Diddy” Combs mingles with “The Hangover Part II” star Bradley Cooper on the black carpet. (Chris Pizzello / Associated Press)