Fool's Gold (2009)

A species of humanoid Pygmy Goat-like aliens come to Earth for a Popcorn Festival in Walton. These aliens feed on popcorn and produce solid gold poop, which keeps the town running. Ben, Gwen, and Kevin are called in by one of the aliens named Orb, who has lost track of his friend, Decka. Mayor Coleman has kidnapped Decka in hopes of having a constant supply of gold, but when he feeds the alien meat, he morphs into his primal form that will multiply uncontrollably if it absorbs enough energy. After being told that the species cannot digest silicon, Ben sacrifices himself by feeding Decka an army of Echo Echos, causing him to vomit up everything he ate, including Ben, and return to normal. He and Orb then leave in their ships, with an angry Decka stating that he will tell everyone what Mayor Coleman did to them and they will never come back. Kevin gives Gwen a locket to remember his human form by before the accident. Though Gwen assures him that she does not care what he looks like, Kevin is adamant in his self-loathing.