Theme from the Monster Cult Mystery

The Monster Cult Mystery was a planned series based on a serpent-like Mayan god named Itzamna, or 'I', which is called upon to modern-day Chicago by a mysterious cult, this way back in 1973. 

Roosting within the top of the Willis Tower (at the time Sears Tower), this awesome fiend begins drizzling blood -- from the bodies of window washers, building workers and rooftop sunbathers alike -- onto the streets of Chicago, with devastating consequences. 

The pilot received highly negative reviews when it was shown via private cinema release thus was binned but through leaked tapes has gained a cult following over the years.