Frank Welker Fred, Scooby Voice Mindy Cohn Velma Voice Grey DeLisle Daphne Voice Matthew Lillard Shaggy Voice Lewis Black Mr. E Guest Voice Clancy Brown Nibiru Guest Voice Linda Cardellini Marcy "Hot Dog Water" Fleach Guest Voice Tia Carrere Judy Reeves Guest Voice Udo Kier Professor Pericles Guest Voice Tim Matheson Brad Chiles Guest Voice Sam Register Executive Producer Spike Brandt Producer Tony Cervone Producer Michael Goguen Director Victor Cook Director Michael Ryan Writer