What does 쥐뿔 mean?

ANSWER: mouse horns

쥐뿔 literally means mouse (쥐) horns (뿔), which is something I have never seen, so they must be really small, right? Actually, mice do not have horns, but Koreans use the expression 쥐뿔같다 (like mouse horns) to refer to something that is either nonexistent or so small that it is insignificant or worthless. You can also say 너 쥐뿔도 모른다 or 너 아는 것이 쥐뿔만큼도 없다 to mean "You don't know anything."

Instead of saying 아무것도 아니다 (It is nothing) or 아무것도 없다 (There is nothing), you can substitute 쥐불 and say 쥐뿔도 아니다 or 쥐뿔도 없다. 

Have you ever seen a dog with horns? Neither have I, but Koreans use the phrase 개뿔 (dog horns) the same way they use 쥐뿔.