Frank Bonner

Jim Hudson (as Frank Boers Jr.)

Edward Connell

David Fielding (as Skip Shimer)

Barbara Hewitt

Susan Turner

Robin Christopher

Vicki (as Robin Snider)

Fritz Leiber Jr.

Dr. Arthur Watermann (as Fritz Leiber)

Louis Clayton

Old man in cave

James Phillips

Reporter Sloan (as Jim Phillips)

Patrick Burke

Doctor Branson

Sharon Gray

Nurse

Jim Duron

The Green Giant