The Hangover Part II did not have the full support of my entire cast and crew." Liam Neeson replaced Gibson after being invited by Cooper, who worked with Neeson on "The A-Team", to take the part. Neeson, a fan of the first film stated, "I just got a call to do a one-day shoot on 'Hangover 2' as a tattooist in Thailand, and that's all I know about it". Gibson was reportedly furious over the decision. A source close to Gibson stated, "He doesn't understand why Mike Tyson, a drug user who turned his life around, was given a chance while Mel was kicked
The Hangover Part II Phillips raised concerns after he joked that Crystal had become addicted to cigarettes after learning to smoke them for the film. Philips later explained that Crystal never actually held a lit cigarette on the film's set and the smoke was added digitally in post-production. Despite this, PETA protested about Crystal's appearance in the film for use of exotic animals for entertainment purposes and the film does not carry the American Humane Association's disclaimer that "no animals were harmed" since the group was denied set visits. In an interview with "New York" magazine, Ken Jeong responded to criticisms of the character