Grey DeLisle Daphne Blake (voice) Stephen Stanton Peanut Vendor (voice) Kari Wahlgren Female Peasent (voice) Frank Welker Scooby-Doo / Fred Jones / Monster (voice) Kate Micucci Velma Dinkley / Sandi (voice) Matthew Lillard Shaggy Rogers (voice) Nick Frost Merlin (voice) Greg Ellis Herald / Herman Ellinger / British Passenger (voice) Jason Isaacs King Arthur Pendragon (voice) Spike Brandt Mr. HB (voice) Trevor Devall Man Cat (voice) Fred Tatasciore Black Knight (voice)