John Landis's "An American Werewolf in London" is proof positive of how well the comedy and horror genres can function alongside each other quite well in the same movie, without each element cancelling the other out. Unfortunately, some viewers just couldn't appreciate it at the time - thinking Landis should have made up his mind what kind of movie he was making - but it's now rightfully regarded as one of the top movies of its kind, made at a time when wolf-themed movies were now back in vogue, with "The Howling" and "Wolfen" released the same year. Writer / director Paul Davis is the man behind this extremely comprehensive, feature length (it actually has a running time similar to that of the actual movie) look at the making of this classic. He occasionally appears on screen to give us background information, and one major appeal of this documentary is seeing him revisit a couple of the old familiar locations, even if in the case of the pub The Slaughtered Lamb the look has changed over the years. "Beware the Moon" mostly consists of sit-down interviews, and it's a delight just how many people among cast and crew take part, including writer / director Landis, principal actors David Naughton, Jenny Agutter, Griffin Dunne, and John Woodvine, makeup effects expert Rick Baker (who deservedly won the Oscar for his work), and crew including producer George Folsey, cinematographer Robert Paynter, editor Malcolm Campbell, art director Leslie Dilley, and others. The expected topics get covered, from the genesis of the project to its execution, the various challenges of shooting, Landis's vision of shooting key scenes, the creation of that incredible transformation scene, and the aftermath / legacy of the release. "Beware the Moon" is informative, engaging, and a treat to watch, with the participants very willing to share all of their memories and anecdotes. Really, this is a perfect companion piece to the movie, and unless some viewers don't really want to see / hear some of the secrets behind the magic, it's a fine look into the whole movie making process. Stay tuned for funny outtakes during the closing credits. 10 out of 10.