Beer Money (2001)

Tim, a failed weatherman, returns to his small hometown to hang out with his high school friends, Rut, a fat jock and Neal, a bald geek. They go camping and see a UFO landing. They hide in the bushes and watch as a small green alien rummages through their packs and eats their food. With the idea that they could make enough beer money for life, Rut shoots the alien as it is making its way back to the ship. The helpless alien has the ability to regenerate, though, and Rut has to injure it several more times in various cruel and violent ways. They also torture the alien to try to get it to talk. A female friend comes to the rescue and convinces Tim that they must let the alien go home.