Breeders (1997) - An alien ventures to Earth on a meteorite and procreates with humans to preserve its species while obliterating the human race.
Bug (2006) - A lonely lesbian binges on alcohol and drugs to deal with the painful disappearance of her son. She ends up living in a skid row motel and begins receiving silent phone calls that she believes are her ex-husband. She then meets Peter, a soldier, who she ends up successfully dating at first until Peter tells her that her odd mysterious phone calls originate with the government. She quickly discovers Peter's paranoia when he begins telling tales that can't possibly be true about bugs and how the creatures alongside the government are coming to get him.
Endangered Species (2003) - A killing machine from another world comes to Earth to kill humans.
Gargoyles (1972) - An anthropologist/paleontologist and his daughter stumble upon a colony of living gargoyles during their travels through the Southwestern United States. These creatures simply wish to be left alone.
Septic Man (2014) - Septic Man involves a sewage worker, who is asked to inspect the water system in his city due to water contamination that has been the cause of his area's evacuation, which includes the worker's own pregnant wife. He gets stranded in the sewage and the toxicity gradually transforms him into a hideous creature.
The Ghouls (2003) - Eric Hayes is well below the lowliest rung of the journalistic ladder, preying on police chases, ambulance trips, and random street violence. He pedals his footage to the highest bidder while living on a steady diet of cigarettes and bloodlust, feeding on the misery of others, but he's about to uncover the situation below Los Angeles' streets, who are even more gore starved than he is--the ghouls.