The movie is about Shaggy being turned into a werewolf, and it's up to Scooby, Scrappy and his girlfriend to help him win the race and get turned back to normal. Starring Don Messick as Scooby-Doo and Scrappy-Doo [the latter is his last appearance before his surprise return in the 2002 film], and Casey Kasem as Shaggy. Supervising Director: Ray Patterson. Written by Jim Ryan. Producer: Berny Wolf; Executive Producers: William Hanna and Joseph Barbera. from Hanna-Barbera Productions, Syndicated by WorldVision Enterprises, Inc. - Part of H-B's Superstar 10 movie package.