Villain(s)  Space vampires, alien creatures

Actor(s):  John Carradine, Robert Dix, Vicki Volante, Joey Benson

Brief Description  Horror of the Blood Monsters (1970) is a low-budget, sci-fi horror exploitation film directed by B-movie legend Al Adamson and written by Sue McNair. Infamous for its chaotic production history, the movie is a cinematic patchwork stitched together from entirely different films, most notably a 1956 black-and-white Filipino adventure movie called Tagani.

Plot:
To disguise the spliced-in footage, Adamson tinted the black-and-white scenes in bright, solid colors—such as red, green, and yellow—and marketed the visual gimmick as "Spectrum-X". The film was released under various alternative titles, including Vampire Men of the Lost Planet and Creatures of the Prehistoric Planet. In the near future, Earth is gripped by a sudden and violent plague of intergalactic vampires who are killing citizens and terrorizing the globe. Renowned scientist Dr. Rynning (played by John Carradine) determines the cosmic radiation trace of the vampire virus. He assembles a team of astronauts aboard the rocket ship XB-13 to trace the infection back to its planet of origin. The space journey faces unexpected malfunctions, forcing the crew to make an emergency landing on an uncharted, prehistoric planet engulfed in strange "chromatic radiation".

While exploring the monochrome wilderness, the crew faces a barrage of bizarre dangers. They encounter aggressive dinosaurs (stock footage of real-life lizards blown up to look giant), snake-men, mutant lobster creatures, and winged simians. The astronauts discover two warring humanoid factions: The Tagani: A peaceful, primitive cave-dwelling tribe. The Tubeton: A brutal, fanged race of subterranean vampire-men who prey on the Tagani. The Escape: Dr. Rynning uses advanced Earth technology to alter the brainwaves of a Tagani woman, Lian Malian, enabling telepathic communication. The astronauts ally with the Tagani to fight off the Tubeton vampires. To fuel their damaged ship and return home, the crew successfully refines a vein of crude oil found deep within the native caves, escaping the planet with the data needed to cure Earth.