knight
Explanation
A knight approaches a tower where a princess is imprisoned and calls out: "Princess! I see you are locked in the tower! Yet you have managed to look hygienic and hot somehow!" The princess responds: "Yes! Help, Sir Knight! Save me!" and urges him to come closer before the dragon returns. The final panel pulls back to reveal that the "princess in the tower" is actually an anglerfish-style lure -- the tower is the dangling appendage of a massive creature lurking in a moat or pit, using the princess as bait to lure the knight closer.
The joke subverts the classic fairy-tale "knight rescues princess from tower" trope by revealing it to be a predatory trap, modeled on the anglerfish, which uses a bioluminescent lure to attract prey in the deep ocean. The knight's observation that the princess looks suspiciously well-groomed for someone locked in a tower serves as foreshadowing -- she looks too good because she is not real, she is bait. The comic plays on the idea that fairy-tale conventions (beautiful princess, conveniently accessible tower, absent dragon) are themselves suspiciously convenient, almost as if designed to lure gullible knights to their doom. It is both a nature joke and a fairy-tale deconstruction.