Sahasrapad took pleasure in mocking and teasing people. He had a friend named Kandarbha. Kandarbha had practised great yogic exercises and meditation for many years. It had given him many supernatural powers. However he had an inherent fear of snakes. One day, Sahasrapad threw a creeper at Kandarbha and shouted that a snake had fallen on his shoulders from the overhanging branch of a tree. It frightened Kandarbha so much that he fainted because of the shock.
On regaining his senses, he expressed his anger by cursing Sahasrapad to be born as a serpent in his next birth. The curse of an achieved saint never goes to waste. In his next birth, Sahasrapad had to live as a snake. Sahasrapad had to pay a heavy penalty for playing a prank on a saintly person.
Moral
A joke should not harm someone physically or emotionally. Insulting remarks and actions always produce dangerous results.
Source: Pragya Tales Part 2