Roy Barcroft
The Purple Monster
Acting
James Craven
Dr. Cygnus Layton
Acting
Dennis Moore
Craig Foster
Acting
Linda Stirling
Sheila Layton
Acting
Bud Geary
Hodge Garrett
Acting
Joe Whitehead
Stewart
Acting
Fred Howard
Prof. Crandal
Acting
Rosemonde James
Helen
Acting
Mary Moore
Marcia
Acting
John Davidson
Emperor of Mars
Acting
Wheaton Chambers
Prof. Benjamin
Acting