A tanner was driving his donkey and his horse to market, and the donkey staggered under the weight of his load.
"Help me, horse!" said the donkey. "I need you to take just a little bit of the load. Have mercy!"
"Bearing the load is your job!" replied the horse. "I'm no donkey."
Soon afterwards, the donkey collapsed and died.
The tanner skinned the donkey, and then he put the donkey's load on the horse, along with the donkey's skin.
"Woe is me!" groaned the horse. "I refused to help the donkey, and now I'm bearing the whole load myself."
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 258 in the book, which is Perry 181.