William Hopper
Colonel Robert Calder
The first spaceship to visit Venus crash lands in the sea, freeing a small native Venusian creature called the Ymir. Eventually growing to enormous size, it threatens the city of Rome.
Colonel Robert Calder
Marisa Leonardo
Dr. Leonardo
Dr. Judson
Maj. Gen. A.D. McIntosh
Commissario Unte
Signore Contino - Government Official
Dr. Sharman
Pepe
Fisherman Mondello (uncredited)
Fisherman Verrico (uncredited)
Reporter Reynolds (uncredited)
Reporter Maples (uncredited)
Felix Roi, a French reporter (uncredited)
Farmer (uncredited)
Man Feeding Elephant (uncredited) / Visual Effects
1st Reuters News Correspondent (uncredited)
Dr. Koruku - Japanese Scientist
Director
Screenplay
