Rick Morales Director, Producer Frank Welker Fred Jones, Scooby-Doo Voice Grey DeLisle Daphne Blake Voice Matthew Lillard Shaggy Rogers Voice Kate Micucci Velma Dinkley Voice Dee Bradley Baker Sea Creature, Malt Shop Walt, Zombie Voice JB Blanc Atticus Fink, Director Voice Christian Lanz Bryan Lakeshore, Mummy Voice Scott Menville Junior Voice Cassandra Peterson Drella Diabolique Voice James Arnold Taylor Chet Brickton, Narrator Voice James Krieg Screenwriter Duane Capizzi Screenwriter