 Seann William Scott , famous for portraying Steve Stifler in the 1999 film American Pie , was hired as class clown Billy Hitchcock . Scott admired the film , and felt that " it 's [ as ] dark and eerie as any Twilight Zone " . He laughed at his role , saying that " [ he ] is lacking some social skills , he doesn 't have quite a few friends , and he 's like the tag @-@ along " . Scott was surprised when in the script his character was written as fat . The writers eventually changed it for Scott . 
