In , you play as Cryptosporidium-137 (or Crips-137 for short), a highly advanced alien sent to Earth to harvest human brains for the aliens' leader, Pod President Psychlos. Your mission is to infiltrate human society, wreak havoc, and gather brains while pretending to be a human. With your advanced psychic powers, you can possess and control humans, animals, and even buildings, leading to hilarious and creative chaos.