Nasruddin heard squawking from the henhouse during the night. "It must be a thief," he thought, and he ran outside, where he found a man creeping away from the henhouse.
By the light of the moon, Nasruddin could clearly see a rooster's tail-feathers sticking out from under the man's cloak.
"Give me back my rooster, you thief!" shouted Nasruddin.
The man stood up straight and answered back, "Sir, please believe me! I have absolutely no idea what you're talking about."
"And do you think I'm going to believe you," Nasruddin replied, "or am I going to believe the rooster's tail-feathers?"
Inspired by: Mulla's Donkey and Other Friends by Mehdi Nakosteen
Notes: This story is on p. 106 of the book. Compare the famous story of Nasruddin and his donkey: Who Are You Going to Believe?