During experiments to find a cure for Alzheimer's disease, a genetically-enhanced chimpanzee uses its greater intelligence to lead other apes to freedom.

A hormone intended to alter the breeding cycle of rabbits overrunning ranchlands instead turns them into flesh-eating, 150-pound monsters. Stuart Whitman, Janet Leigh, Rory Calhoun, and DeForest Kelley are among the intrepid humans facing the behemoth bunnies. They use guns, flames, and dynamite to subtract them. But the rampaging rabbits know how to multiply. Can anything stop these hare-y scary monsters?