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
