A saint saw a cat chasing a mouse and used his supernatural powers to turn the mouse into a cat, saving its life. When a dog chased the cat, the saint turned the cat into a dog. Later, when a lion attacked the dog, the saint turned the dog into a lion.
The villagers, who knew the secret of this new lion, would make fun of it—it was an insignificant mouse that had become a lion. The lion believed everyone would tease it as long as the saint was alive. The saint saw the lion approaching and understood its intentions.
"You are ungrateful and not worthy of being a lion," said the saint. "Become a mouse again."
Thus, the lion shrank and became a mouse once more.
Be grateful and humble, or you may lose what you’ve gained.