The Invisible Monster
VoltarElenco
Richard WebbLane Carson
Aline TowneCarol Richards
Stanley PriceThe Phantom Ruler
Lane BradfordBurton
John CrawfordHarris
George Meeker"Harry Long"
Edward KeaneWarren Madison
Dale Van SickelOtto Wagner, aka "Frank Martin"- Douglas Evans"James Hunter"
John Hamilton"Henry Miller"
Roy GordonMr. Moore
Harold GoodwinKirk - Body-Shop Henchman [Ch.11] (sem créditos)
Marshall ReedRoadblock Cop [Ch. 1, 7]
David SharpeGarage Watchman [Ch. 3] / Armored Car Guard [Ch. 11]
George MagrillHenchman Sam [Ch. 4-5]
Guy TeagueDecoy & Dumptruck Henchman [Ch. 5, 7]
Tom SteeleHenchman Bill 'Mack' Haines [Chapters 5, 10]
Eddie ParkerBarn Henchman Stoner [Ch.8]
Keith RichardsDoctor [Ch. 12]- Duke TaylorSecond Roadblock Cop [Ch. 1 bit]
- Mark StrongBank Watchman [Ch.1 bit]
- Bert LeBaronCrooked Watchman [Ch. 2 bit]
Frank O'ConnorChemical Truck Cop [Ch. 5 bit]- Forrest BurnsWatchman Joe [Ch. 5 bit]
Carey LoftinDynamite Henchman Dirk [Ch. 6 bit]- Tom MonroeCave Policeman [Ch. 7 bit]
Howard M. MitchellSecond Garage Watchman [Ch. 7 bit]
Charles SullivanSquadcar Cop [Ch. 7 bit]- George VolkSecond Armored Car Guard [Ch. 11 bit]