Mr. Mustela (voice)
Lucky
Mort Rifkin
Mr. Crocus
Rex (voice)
Frank
Rex (voice)
Dr. Derek
Principal Miller
Mr. Woodley (voice)
Kliegler
Self (archive footage)
Mr. Willis
Gary the Gadget Guy (voice)
Rex (voice)
The Farmer
Psychotherapist
Mr. Papadopoulos
Halvard Solness
Rex (Voice)
Clarence
Gideon Rosen
Rex (voice)
Dr. Van Helsing
Rex (voice)
Rex (voice)
Calico (voice)
Rex (voice)
Dr. Christian Burr (uncredited)
Booker / Broker / Lancealot Squarejaw / Broker / Booker / Lancelot Squarejaw
Himself
Mr. Gibbles (voice)
Mr. Gibson
Baron Von Westphalen
Rex (voice) (archive footage)
Teacher / Math Teacher (uncredited)
Munk (voice)
Billy (voice)
Barnacle Paul (voice)
Principal Fetchit (voice)
Gilbert Huph (voice)
Principal Crosby Strickler (voice)
Herman
Colonel Wilson
Mr. Gelb
Rex (voice) (uncredited)
George Bond
Gene
Rex the Green Dinosaur (voice)
Dr. Elliott Coleye
Tarzan Chimp (voice)
Furnaceman
Arthur Blake
Marty
Victor Finley
Labrador MC (voice)
Rex (voice)
Mr. Wendell Hall
Stan Spiegel
Echidna (voice)
Canadian Prime Minister Clark MacDonald
Cosmo
Principal Mazur (voice)
Horatio Byrd
Mr. Little
Larry
Cashpot
Sibor, Semage's Beau
Everett Willits
Simon Carr
Translator
Dr. Fishbinder
Oiseau
Vizzini
John Lahr
Masked Avenger
Henderson's Attorney
Mike Hoover
Father Abruzzi
Dr. Elliot Fibel
Interviewer
Mr. Pardon
Turtle
Frank Judd
Harold DeVoto
Jules Goldfarb
Otto Jaffe
Professor Silverfish
Oliver
Birthday Party Guest (uncredited)
Wally Shawn
Mugger
Waiter
Eric Van Dongen
Assistant Insurance Man
Workshop Member
Jeremiah
