We are all very familiar with the Arabian Nights and the story of the Fisherman and the Devil. A very similar fable in China is called Master Dongguo and the Wolf of Zhongshan, or An Unrequited Kindness. 

Master Dongguo, a pedantic teacher and follower of Mohism, was ready to help anyone in distress, whoever it might be and regardless of the circumstances. One day on a journey through the Zhongshan Mountain, he came across a wounded wolf being pursued by hunters. At bay, the wolf sweetly begged the master to help him. The old man saw a chance to act on the Mohist doctrine of "universal fraternity". At the risk of incurring the displeasure of the hunters, he took the books out of his travelling bag and put the wolf in it. When the hunter came along and inquired if he had seen a wolf, Master Dongguo lied, saying that he had noticed nothing unusual. The hunters galloped on.

However, when the wolf was let out of the bag, he showed his true self. He said he was hungry; since the master was so kind as to have helped him once, he might as well do it again by allowing himself to be eaten. Now it was Master Dongguo's turn to run.

Just then, a farmer came along and asked what was the matter. Master Dongguo and the wolf gave their respective arguments and asked him to make a judgment. The farmer thought over the situation for a few moments and said, "I don't believe the story either of you told me. The bag's so small. How could Mister Wolf get into it? Maybe you should show it to me?"

So the wolf once again got into the bag and the farmer immediately tied up the bag.

"You are too naive. You treat beasts like this with kindness, but their evil nature can never change,?said the farmer. He then killed the wolf with his hoe. Only then did the master wake up to reality.

This fable is so well known among the Chinese that "Master Dongguo" is a synonym for a pedantic person who is unable to see the greater picture, and the "Wolf of Zhongshan", for an ingrate.