pigs may fly

English edit

Alternative form of pigs might fly
- 1913, Arthur Conan Doyle, “(please specify the page)”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton, →OCLC:
  "Pigs may fly. Yes, sir, pigs may fly - but they don't. It is not worth arguing with you. Challenger has filled you with his nonsense and you are both incapable of reason."