Alan Garner
Alan, portrayed by Zach Galifianakis in "The Hangover," is a socially awkward and childlike character who is Doug's future brother-in-law. Known for his erratic behavior and ADHD, Alan adds a significant layer of humor to the film with his unpredictable actions and quirky personality. His role as one of the main characters in the movie's plot is crucial, especially since he is often the source of comedic situations and mishaps during the chaotic bachelor party in Las Vegas.
