"A famous scientist invents a humanoid robot (the titular "monster"), so a greedy rival scientist plans to steal it for use in his criminal plans. His henchmen often kidnap a trained gorilla (the titular "ape") from the zoo, to aid in the schemes."
Robert Lowery
as Ken Morgan
George Macready
as Prof. Ernst
Ralph Morgan
as Prof. Franklin Arnold
Carole Mathews
as Babs Arnold
Willie Best
as Flash
Jack Ingram
as Dick Nordik
Anthony Warde
as Joe Flint
Ted Mapes
as Joe Butler
Eddie Parker
as Blake
Stanley Price
as Mead
Charles King
as First Cop with Thor
Kenneth MacDonald
as Police Inspector Hamilton
Bud Osborne
as Mason
Ray Corrigan
as Thor
John Elliott
as Prof. Marsden
Kit Guard
as Zoo Guard
Howard Bretherton
Director
Royal K. Cole
Screenplay
Sherman L. Lowe
Lee Zahler
Music
Dwight Caldwell
Editor
Earl Turner
Stunts
L. William O'Connell
Director of Photography