Collette Sunderman Director, Costume Design Maxwell Atoms Director, Screenwriter, Executive Producer Christina Sotta Director Melchior Zwyer Director Frank Welker Scooby-Doo, Fred Jones, Monster Voice Grey DeLisle Daphne Voice Matthew Lillard Shaggy Rogers Voice Kate Micucci Velma Dinkley, Sandi Voice Jonny Rees Herald, Herman Ellinger, British Passenger Voice Jason Isaacs King Arthur Pendragon, Winston Pilkingstonshire, Thundarr Voice Jeremy Adams Screenwriter Spike Brandt Executive Producer James Krieg Executive Producer Sam Register Executive Producer Robert Ehrenreich Film Editing Michael Mangan Film Editing Robert J. Kral Original Music