A mutant who has to eat human brains to survive is hunted by the two FBI agents.
Tropes used in this episode:
Black Eyes of Evil: The brain-eating struggling monster Rob has these, which he hides with contacts.
Blackmail: One of Rob's coworkers realizes that he is behind the murder that brought Murder and Scully in, and tries to blackmail him after their investigaton digs up his own past as an ex-con, which lead to him being fired by Lucky Boy restaurant.
Burger Fool: The monster of the week works at the burger joint Lucky Boy.
Horror Hunger: Rob is struggling to keep his hunger for brains in check, which he tries to satiate with rotten meat from his workplace.
Monster of the Week: From the monster's point of view. Mulder and Scully are very background characters in this episode.
Mook Horror Show: The episode is told from the perspective of a monster who doesn't understand what he is, can't help what he does, and is pursued relentlessly by FBI agents who seem frighteningly perceptive.
Neat Freak: The monster has an immaculately clean apartment, which Mulder finds unusual for a twenty-something male living alone. He has to do so to keep from getting caught, cleaning up after eating victims.