Characters go to bed for the night. Monster appears, but doesn't do anything significant. The following night, the least desirable character is killed. People wonder where undesirable character is, but don't look too hard. One of them finds some obvious clue the monster left behind.
Monster kills second least-desirable character.
Main character finds out about monster and tries to convince everybody else that it exists. Monster kills somebody else, but is witnessed by other people who try to kill it and run away. Movie ends and the film's director goes back to picking up welfare checks. Be sure to make one of them fat. A couple orderlies or doctors or surgeons or fast food cooks or astronauts or whatever the hell they were supposed to be are killed by some hairy guy in a mask .