Robert Lowery

Ken Morgan

George Macready

Prof. Ernst

Ralph Morgan

Prof. Franklin Arnold

Carole Mathews

Babs Arnold

Willie Best

Flash

Jack Ingram

Dick Nordik

Anthony Warde

Joe Flint

Ted Mapes

Joe Butler

Eddie Parker

Blake

Stanley Price

Mead

Charles King

First Cop with Thor

Kenneth MacDonald

Police Inspector Hamilton

Bud Osborne

Mason

Ray Corrigan

Thor

John Elliott

Prof. Marsden

Kit Guard

Zoo Guard

Howard Bretherton

Director

Royal K. Cole

Screenplay

Sherman L. Lowe

Screenplay

Lee Zahler

Music

Dwight Caldwell

Editor

Earl Turner

Editor

Ted Mapes

Stunts

Eddie Parker

Stunts

L. William O'Connell

Director of Photography