Brainiac

In 1661 Mexico, the Baron Vitelius of Astara is sentenced to be burned alive by the Holy Inquisition of Mexico for witchcraft, necromancy, and other crimes. As he dies, the Baron swears vengeance against the descendants of the Inquisitors. More then 300 years later, a comet that was passing overhead on the night of the Baron's execution returns to earth, bringing with it the Baron in the form of a horrible, brain-eating hideous monster that terrorizes the Inquisitor's descendants for all eternity.