EP Roger Corman unleashes hideous aqua beasts and horrors from outer space in two of his most memorable thrillers. A mutant stalks the Earth when the body of a dead astronaut is used as an alien incubator in Night of the Blood Beast (1959). Equally revolting is Attack of the Giant Leeches (1958), which stars B-movie siren Yvette Vickers (Attack of the 50-Foot Woman).