Its The Purge meets werewolves this holiday season, as action star Frank Grillo takes on the iconic monsters in the newly released trailer for this Decembers action horror thrill-ride, Werewolves. The movie boasts the kind of killer high-concept that only comes around once in a blue moon, with Grillo leading the fight after a rare supermoon event triggers a gene in every human being and turning them into a werewolf if they enter the moonlight.