Lon Chaney
Professor Echo / Granny O'Grady

Mae Busch
Rosie O'Grady

Matt Moore
Hector McDonald

Victor McLaglen
Hercules

Harry Earles
Tweedledee aka Little Willie

Matthew Betz
Detective Regan

Edward Connelly
Judge

William Humphrey
Attorney for Defense

E. Alyn Warren
Prosecuting Attorney

Margie Angus
Twin (uncredited)

Mary Angus
Twin (uncredited)

Walter P. Cole
Human Skeleton (uncredited)

Carrie Daumery
Pet Shop Customer (uncredited)

Delmo Fritz
Sword Swallower (uncredited)

Alice Julian
Fat Lady (uncredited)

Peter Kortes
Sword Swallower (uncredited)

Mickey McBan
Boy Watching Hercules' Act (uncredited)

Wilmuth Merkyl
Jeweler (uncredited)

John Millerta
Wild Borneo Man (uncredited)

Louis Morrison
Police Commissioner (uncredited)