Erica Beck Desmond T. Doss Sauraseni Maitra Captain Glover Kristen Bell Sgt Howell Idina Menzel Dorothy Schuttle Josh Gad Smitty Ryker Jonathan Groff Tom Doss Evan Rachel Wood Bertha Doss Sterling K. Brown Lieutenant Manville Alfred Molina Colonel Stelzer Rachel Matthews Andy 'Ghoul' Walker Jason Ritter Milt 'Hollywood' Zane Martha Plimpton Vito Rinnelli Ciarán Hinds Tex Lewis Vincenzo Amato Harold "Hal" Doss Jeremy Sisto Irv Schecter Stephen J. Anderson Lt. Cooney Maia Wilson James Pinnick Gavin MacIver-Wright Japanese Officer Matthew Lillard Shaggy Rogers (voice) Thea White Muriel Bagge / Rich Old Lady (voice) Grey DeLisle Daphne Blake / Frau Glockenspiel (voice) Frank Welker Scooby-Doo / Fred Jones (voice) Kate Micucci Velma Dinkley (voice) Jeff Bennett The General / Self Help Book (voice) Paul Schoeffler Katz / Le Quack / Narrator (voice) Marty Grabstein Courage / Mr. McGill (voice) Jeff Bergman Eustice Bagge / Computer / Mayor of Nowhere (voice) Chuck Montgomery The Lieutenant / Mr. Glockenspiel (voice)