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, he swears vengeance. 300 years later, a comet passing overhead on the night of the Baron's execution returns to earth, bringing with it the Baron as a horrible, brain-eating monster that terrorizes the Inquisitor's descendants.