emerge as the existence of many mystery-solving groups in the past of Crystal Cove comes to light and unearthly forces repeatedly intone the word " Nibiru "... Characters Scooby-Doo (Frank Welker) Shaggy Rogers (Matthew Lillard) Fred Chiles (Frank Welker) Daphne Blake (Grey DeLisle) Velma Dinkley (Mindy Cohn) Mayor Janet Nettles (Kate