eat-5
Explanation
This comic features an encounter between a human and an alien. The human exclaims "Oh my God, aliens! Are you going to eat us?" The alien responds "Not yet." When pressed, the alien explains the rule: "The rule is you can only eat beings 5 times dumber than you. Right now, more like 4 times. Getting dangerously close though."
In the next panels, the human protests: "We have homes, reverse-osmosis water, gentle castration, politics in many styles, edible stickers, food..." The alien responds "So much to go over now," and the human continues listing achievements that seem less and less impressive. The alien says "Surely you don't think you're being persuasive," to which the human apparently does.
The joke satirizes humanity's inflated sense of its own intelligence and accomplishments. The alien's "5 times dumber" rule creates a scenario where humans are dangerously close to being dumb enough to eat, and the human's attempt to argue for humanity's intelligence backfires spectacularly. The list of "accomplishments" the human cites -- reverse-osmosis water, "gentle castration," "politics in many styles," and "edible stickers" -- are either mundane, bizarre, or arguably evidence against human intelligence. The humor mechanism is dramatic irony: the human is unknowingly proving the alien's point by offering a terrible defense of human intelligence. This is a common SMBC theme of poking fun at human self-importance from a cosmic perspective.