pirate
Explanation
The Joke
A pirate has captured someone and declares "I'm a time traveler! Tell me where the treasure is hidden!" The captive responds "Never! Traveler? Really?" expressing skepticism. The pirate then threatens that he will change the word "pirate" to something "less woody and rough" so that it will "sound stupid to children." The final panel reveals his threat: "I'll never get rid of the termites in my poop!" with "poop" being the replacement word, and the captive cries "The die is cast!"
The joke plays on a counterfactual time-travel scenario where a pirate goes back in time not to find treasure, but to leverage his ability to rename things. The pirate's real power is linguistic -- he can retroactively change what the word "pirate" becomes, thereby threatening to make the concept of piracy sound ridiculous to future generations. The captive's dismay at the word "poop deck" (or similar pirate terminology becoming absurd) is what breaks him.
The Humor
The humor comes from the absurd inversion of what a time-traveling pirate would do with that power. Instead of seeking treasure or changing historical battles, the pirate weaponizes etymology itself. The punchline -- that pirate terminology would include the word "poop" -- is funny because it already does (the poop deck is a real nautical term), but framing it as a deliberate act of linguistic sabotage makes the mundane seem like a devastating threat. The captive's dramatic surrender ("The die is cast!") over something so trivial amplifies the comedy.