Children's animated adventure feature following Scooby-Doo and the Mystery Inc. gang as they investigate strange goings-on at a circus. Scooby (voice of Frank Welker), Shaggy (Matthew Lillard), Fred (also Welker), Daphne (Grey DeLisle) and Velma (Mindy Cohn) visit Brancusi Circus and end up performing in the show but they soon find themselves trying to solve a mystery involving a terrifying werewolf that has been wreaking havoc at the big top.