The Dog and the Wolf

A Dog was lying in the sun before a farmyard gate when a Wolf pounced upon him and was just going to eat him up; but he begged for his life and said, "You see how thin I am and what a wretched meal I should make you now: but if you will only wait a few days my master is going to give a feast. All the rich scraps and pickings will fall to me and I shall get nice and fat: then will be the time for you to eat me." The Wolf thought this was a very good plan and went away. Some time afterwards he came to the farmyard again, and found the Dog lying out of reach on the stable roof. "Come down," he called, "and be eaten: you remember our agreement?" But the Dog said coolly, "My friend, if ever you catch me lying down by the gate there again, don't you wait for any feast."

Once bitten, twice shy.