Jim Hudson (as Frank Boers Jr.)
Frank Bonner
David Fielding (as Skip Shimer)
Edward Connell
Susan Turner
Barbara Hewitt
Vicki (as Robin Snider)
Robin Christopher
Dr. Arthur Watermann (as Fritz Leiber)
Fritz Leiber Jr.
Old man in cave
Louis Clayton
Reporter Sloan (as Jim Phillips)
James Phillips
Doctor Branson
Patrick Burke
Nurse
Sharon Gray
The Green Giant
Jim Duron
Special Effects
David Allen
Producer
Dennis Muren
Director
Music
Truman Fisher
Assistant Director
Mark Thomas McGee
Jim Danforth
Writer