An onager who had strayed from his herd in search of grass saw a donkey eating a bundle of barley straw.
"That barley straw looks tasty," thought the wild donkey, "and how fat he looks. He must be a lucky donkey indeed!"
Then the wild donkey watched as a man put heavy bundles on the donkey's back. The man shouted at the donkey, and then he threatened the donkey with a whip.
At that, the onager turned and ran. "I was wrong; that donkey is not lucky after all. I would never sell my freedom in exchange for barley straw."
Inspired by: Mille Fabulae et Una, a collection of Latin fables that I've edited, free to read online. I am not translating the Latin here; instead, I am just telling a 100-word version of the fable.
Notes: This is fable 147 in the book, which is Perry 183. Onagers are wild donkeys who used to range throughout the Middle East, although today they live mostly in the deserts of Iran, Pakistan, and India. More information at Wikipedia.