"Los Monstruos del Terror (The Monsters of Terror), also known as Dracula vs. Frankenstein and Assignment Terror, is a 1970 Spanish/German/Italian horror film that is the third in a series featuring the werewolf, Waldemar Daninsky, played by Paul Naschy. The film was originally slated to be called The Man Who Came From Ummo, referring to the Michael Rennie character.
It was shown on American TV in the 70's as Assignment Terror, and was later released on VHS as Dracula vs Frankenstein (not to be confused with the infamous Al Adamson film of the same name). Although most TV prints of this film are faded "pan and scan" messes, there is a DVD release from Luminous Film and Video Wurks that preserves the letterboxed image, has nice color and is apparently uncut (although a bit splicy).
Lead actor Paul Naschy also wrote the screenplay. The original shooting title was The Man Who Came from Ummo (El Hombre que Vino de Ummo), but the producer changed it to The Monsters of Terror. Direction was split between two people, Tulio Demichelli and Hugo Fregonese. Filming was interrupted because of financial difficulties and also resulted in the script not being filmed as it was written. Whole segments of the script involving flying saucers and a Golem were never filmed as the result of sorely lacking funds."