By the time An American Werewolf in London hit theaters,John Landis was a household name. His preceding directorial efforts — 1977's Kentucky Fried Movie, 1978's Animal House and 1980's The Blues Brothers — found him the sort of comedy street cred most filmmakers can only dream of. While he stayed real to his comedy roots with the 1981 werewolf-themed movie, or Landis branched out from the confines of the genre and added some gruesome horror to the mix.
Source: blastr.com