The Wolf and the Lamb

Once a wolf went to a stream to quench his thirst with water. While he was drinking water, he saw a lamb that was also drinking water over there.
At the sight of lamb, his mouth began to water. He turned to the lamb and  said, "How dare you make the water muddy? Can't you see that I am drinking water from the same stream?"
The lamb got so much frightened that it could not speak for a while. Then it replied, "Sir, I beg your pardon. The water is running down from you to me. How can I make it muddy?"
The wolf said, "But you bleated me and called me names last year" The lamb replied, "Sir, I was not even born then. How could I abuse you last year?"
The wolf, who was determined to eat the poor  lamb, said to it, "Then it must have been your father or mother or brother. You must suffer for your race." Saying so, the wolf caught him, tore him to pieces and ate him up.
Moral:
Any excuse is good enough to serve an evil-doer.