I heard a story once, and I think it’s from some famous source, but I can’t remember what the source is.
The story has it that an entertainer came to a small town, and was drawing a crowd. The entertainer’s schtick was doing impressions of various animals: He made a whinnying sound, and the audience all agreed that he sounded exactly like a real horse, and then he made a mooing sound, and everyone agreed that he sounded just like a cow, and so on. Finally, he oinked like a pig, and one member of the audience, a farmer, exclaimed that that was nothing like what a pig really sounded like. No, this is what a pig sounds like. The townsfolk all laughed at the farmer’s feeble attempt which sounded nothing at all like a pig, and so the farmer revealed that he had a real pig hidden under his coat, and that it was the pig that made the sound, not him. At which point, of course, the townsfolk ran the farmer out of town, and continued listening to the “realistic” entertainer.
I want to say that this was one of Aesop’s fables, except of course that the main characters are humans, and I don’t think Aesop ever had human characters. And it’s always possible that it’s a new story, just with a veneer of antiquity painted over it by the teller. But it has to have been from somewhere.