Wolfs in Aesop's fables

The Wolf & the Kid

There was once a little Kid whose growing horns made him think he was a grown-up Billy Goat and able to take care of himself. So one evening when the flock started home from the pasture and his mother called, the Kid paid no heed and kept right on nibbling the tender grass. A little later when he lifted his head, the flock was gone.
He was all alone. The sun was sinking. Long shadows came creeping over the ground. A chilly little wind came creeping with them making scary noises in the grass. The Kid shivered as he thought of the terrible Wolf. Then he started wildly over the field, bleating for his mother. But not half-way, near a clump of trees, there was the Wolf!
The Kid knew there was little hope for him.
"Please, Mr. Wolf," he said trembling, "I know you are going to eat me. But first please pipe me a tune, for I want to dance and be merry as long as I can."
The Wolf liked the idea of a little music before eating, so he struck up a merry tune and the Kid leaped and frisked gaily.
Meanwhile, the flock was moving slowly homeward. In the still evening air the Wolf's piping carried far. The Shepherd Dogs pricked up their ears. They recognized the song the Wolf sings before a feast, and in a moment they were racing back to the pasture. The Wolf's song ended suddenly, and as he ran, with the Dogs at his heels, he called himself a fool for turning piper to please a Kid, when he should have stuck to his butcher's trade.

Do not let anything turn you from your purpose

The Wolf & the Crane

A Wolf had been feasting too greedily, and a bone had stuck crosswise in his throat. He could get it neither up nor down, and of course he could not eat a thing. Naturally that was an awful state of affairs for a greedy Wolf.
So away he hurried to the Crane. He was sure that she, with her long neck and bill, would easily be able to reach the bone and pull it out.
"I will reward you very handsomely," said the Wolf, "if you pull that bone out for me."
The Crane, as you can imagine, was very uneasy about putting her head in a Wolf's throat. But she was grasping in nature, so she did what the Wolf asked her to do.
When the Wolf felt that the bone was gone, he started to walk away.
The hungry but unsuspecting Fox, went around the tree as he was told, and in a twinkling the Dog had seized him.
"What!" snarled the Wolf, whirling around. "Haven't you got it? Isn't it enough that I let you take your head out of my mouth without snapping it off?"

Expect no reward for serving the wicked.

The Wolf in Sheep's Clothing

A certain Wolf could not get enough to eat because of the watchfulness of the Shepherds. But one night he found a sheep skin that had been cast aside and forgotten. The next day, dressed in the skin, the Wolf strolled into the pasture with the Sheep. Soon a little Lamb was following him about and was quickly led away to slaughter.
That evening the Wolf entered the fold with the flock. But it happened that the Shepherd took a fancy for mutton broth that very evening, and, picking up a knife, went to the fold. There the first he laid hands on and killed was the Wolf.

The evil doer often comes to harm through his own deceit.