Watch Beware the Moon: Remembering 'An American Werewolf in London' for Free: How to Stream the Movie Online at 123Movies. . Host Paul Davis takes a trip through some of the iconic backdrops of John Landis' 1981 werewolf classic An American Werewolf In London. The original cast and crew tell the story of how the film was made over a quarter of a century ago featuring rare footage and never before seen photos.