Once, while Vardhmankumar was playing with his friends beneath a tree, Indra praised his courage in his royal court. Hearing this, a celestial being decided to test Vardhmankumar's courage by transforming into a black cobra and encircling the tree where the children played. While the other children fled in fear, Vardhmankumar remained unfazed.

To allay the children's fears, he swiftly caught the snake and flung it away.The celestial being then transformed into a child and rejoined the group, purposefully losing in a game against Vardhmankumar. According to the game's rules, the loser had to carry the winner on his shoulders and run around. However, the celestial being began to grow taller in an attempt to frighten Vardhmankumar.

Unperturbed, Vardhmankumar recognized the celestial being and punched him hard on the head to teach him a lesson. The blow was so powerful that the celestial being reverted to his original form. Amazed by Vardhmankumar's courage, the celestial being bowed down to him and exclaimed, "You are truly a Mahavir" (meaning 'very brave'). Henceforth, Vardhmankumar came to be known as "Mahavir." Throughout his life, Mahavir never oppressed anyone and emphasized the importance of controlling the five senses and the mind, stating that true kingship lies in self-mastery rather than conquest. Such was the childhood of Vardhmankumar.