Jack Arnold Director John Agar Prof. Clete Ferguson Actor Lori Nelson Helen Dobson Actor John Bromfield Joe Hayes Actor Robert B. Williams George Johnson Actor Nestor Paiva Lucas Actor Grandon Rhodes Jackson Foster Actor Dave Willock Lou Gibson Actor Charles Cane Police Captain Actor Ricou Browning The Gil Man, Lab Technician Actor Clint Eastwood Jennings Actor William Alland Producer Martin Berkeley Screenwriter William Lava Original Music Herman Stein Original Music Scotty Welbourne Cinematographer Paul Weatherwax Film Editing Alexander Golitzen Art Director Alfred Sweeney Art Director Russell A. Gausman Set Decoration Julia Heron Set Decoration Jay A. Morley Jr. Costume Design