Phineas Worrell is a character in Ernest Scared Stupid.
Phineas is an early ancestor to Ernest, possibly his great, great, great grandfather and apparently the first Worrell to step foot in America. He helped banish an evil demonic troll named Trantor, who had followed him and his people to the "new world" (Briarville is the exact specific location) which resulted in a wide spread hunt for Trantor. Once Trantor had his capture, Phineas had him imprisoned beneath the roots of a twisted oak tree for which him cursed the entire Worrell family. This curse was passed through the generations, making every future descendant increasingly dumber than the last (which kind of explains a few things). Trantor also warned Phineas that "When the face of death covers the moon, one with your blood in his veins shall release me. Then victory will at last be MINE!". These events had rubbed off on Ernest over one hundred years later when he accidentally released Trantor, just as his curse had prophesied, and was forced into a final battle with him.