In one of his rare performances without Bud Abbott, Lou Costello plays a rubbish collector and inventor. When radiation in a nearby cave turns his girlfriend into a giantess, antics ensue as he tries to shrink her using one of his inventions.
| Actor | Role |
|---|---|
 Lou CostelloArtie Pinsetter | Artie Pinsetter |
 Dorothy ProvineEmmy Lou Rossiter | Emmy Lou Rossiter |
 Gale GordonRaven Rossiter | Raven Rossiter |
 Jimmy ConlinMagruder | Magruder |
 Charles LaneStandard Bates | Standard Bates |
 Robert BurtonFirst General | First General |
 Will WrightPentagon General | Pentagon General |
 Lenny KentSergeant | Sergeant |
| RRuth PerrottAunt May | Aunt May |
 Peter LeedsBill Burton | Bill Burton |
 Robert NicholsBank Manager | Bank Manager |
 Veola VonnJackie Delaney | Jackie Delaney |
| JJack StrawPilot | Pilot |
| GGeorge BoyceTownsman | Townsman |