A scientist obsessed with cross-breeding humans and plants conducts secret experiments to create human-plant hybrids, using students as unwitting subjects and discarding his failures to a carnival sideshow run by a man who has performers with real and simulated deformities. When the exploited sideshow "freaks" turn on those who abused them, the professor's creations come back to haunt him. Directed by Jack Cardiff, consciously echoing Tod Browning's Freaks, and starring Donald Pleasence, Tom Baker, and Michael Dunn.