Donald Murphy
Oliver Frank(enstein)

Sandra Knight
Trudy Morton

John Ashley
Johnny Bruder

Felix Locher
Prof. Carter Morton

Wolfe Barzell
Elsu

Harry Wilson
The Monster

Sally Todd
Suzie Lawler

Harold Lloyd Jr.
Don

John Zaremba
Police Lt. Boyle

Robert Dix
Police Det. Bill Dillon

Charlotte Portney
Hysterical Woman

Voltaire Perkins
Mr. Rockwell

Bill Coontz
Loading Dock Foreman

George Barrows
Loading Dock Worker Mack