Body of the Prey (1967)

Dr. Bragan (James Craig) is a workaholic rocket scientist at NASA working on a mission to outer space. The stress of the mission causes him to have a mental breakdown, so his assistant, Dr. Paul Nakamura (Yagi), suggests he takes a vacation in Japan at his abandoned luxury resort to recuperate. Dr. Bragan accepts his offer and flies to Japan. In Japan, Dr. Bragan stays at the defunct hotel of Nakamura with Dr. Noriko Hanamura (Kami), the lovely cousin of his coworker who takes on the role of his assistant. Bragan begins a bizarre experiment in botany in the hotel's secluded greenhouse to prove his theory that humans evolved from plants. With a potted Venus flytrap he brought from America, the scientist grafts it to a Japanese carnivorous oceanic plant to create a hybrid creature that becomes humanoid and requires the blood of mammals to flourish. But Bragan is just as obsessive and moody as he was in America, and his behavior causes Noroko to suspect he is going mad, especially when he secretly takes a victim's "heart blood" to feed it. When his creation, "Sectovorus" uproots and begins moving around on its own, it becomes dangerous and it's not long before the creature begins seeking human victims from a nearby village. The villagers riot and Dr. Bragan must decide between protecting his creation or killing it in order to save mankind. He opts to lure it into a nearby volcano.