This is one of the best-known, non-dubbed Santo filns, chiefly due to its "All Star" lineup of monsters, one of which--the Cyclops--was left over from "La Nave De Los Monstruos" (The Ship of Monsters), a Sotomayor production made ten years earlier; a midget alien with an exposed brain also appears in both films, although its role in this film is minimal. "Santo and Blue Demon Vs. The Monsters" has the "Mystery" credit, listing Alejandro Cruz ( AKA Black Shadow ) "as" Blue Demon's evil duplicate. Maybe the credits are wrong??. To foil his plans for world domination, wrestling superheroes El Santo and Blue Demon battle the mad Dr. Halder and his army of reanimated monsters, This one is a No-Brainer! and considered the best of the Santo-Blue Demon Monster films. Starring Santo, Blue Demon, and Hedi Blue, Uncut Spanish Version with English Subtitles. 1969 Color 85 Minutes on DVD-R.