expression
things that do not exist; horns on rabbits, fur on turtles
A Buddhist-derived yojijukugo used idiomatically to refer to something that is impossible or nonexistent, like a rabbit's horns or a turtle's fur. Rare in everyday speech; mostly encountered in literary or religious contexts.
「兎角亀毛」は、この世に存在しないもののたとえとして使われる。
兎角亀毛 is used as a metaphor for things that do not exist in this world.
A yojijukugo of Buddhist origin, literally 'rabbit horns, turtle fur', referring to impossible or nonexistent things. The exact historical derivation is uncertain, but the phrase is conventionally associated with the idea of something that cannot exist in reality.