Frank Welker Fred, Scooby Voice Mindy Cohn Velma Voice Grey DeLisle Daphne Voice Matthew Lillard Shaggy Voice Frances Conroy Mayor Fred Jones Sr. Guest Voice Udo Kier Professor Pericles Guest Voice Maurice LaMarche Vincent Van Ghoul, Announcer Guest Voice Cree Summer Lady Marmalade Guest Voice Gary Cole Mayor Fred Jones Sr. Guest Voice Sam Register Executive Producer Spike Brandt Producer Tony Cervone Producer Curt Geda Director Victor Cook Director Mitch Watson Writer