by Larry FitzmauriceBuzzFeedBuzzFeed Staff Of course, Mean Girls - and we're talking the original Mean Girls here - wouldn't be what it was without Rachel McAdams' iconic performance as Regina George. (C)Paramount/Courtesy Everett Collection It might shock you to find out, however, that Rachel didn't audition for Regina initially - and not only that, but the film's casting had some specific misgivings about the role she was pursuing.