An invisible monster is terrorizing Sealab and killing everyone. They try to kill it by having Hesh change Sealab's atmosphere, but the monster just kills Hesh and changes it back. Quinn decides to seek out Old Gus, who's seen a lot. Gus has been attacked by the monster, but managed to survive and give Quinn an idea on how to kill it.
With only Quinn, Sparks, Murphy, and Dolphin Boy alive, Quinn locks Dolphin Boy in the reactor room with a vest made of meat to serve as bait for the monster, planning to overheat the reactor core and give the monster a fatal dose of radiation, uncaring that this would also kill Dolphin Boy. Sparks is electrocuted when Murphy's chocolate chip juice spills onto his console. The monster and Dolphin Boy seem to bond at first over being unliked, but the monster shocks Dolphin Boy's finger and calls him fat. Murphy concludes that he and Quinn must get disgustingly fat to avoid being eaten and they head to the mess hall to do so. As they do so, the monster disappears.
The Stinger: Set 33 months later, Quinn and Murphy are disgustingly fat. Murphy reveals they ate Dolphin Boy and they laugh before Quinn suffers a heart attack and dies. Murphy ends up eating Quinn.
- Freeze-Frame Bonus: Frylock can be spotted among the food in The Stinger.
- Intentional Weight Gain: Quinn and Murphy deliberately make themselves disgustingly fat under the assumption the monster won't kill them if they do.
