"The cowherd men, headed by Nanda Maharaja, spent that night on the bank of the Sarasvati. They fasted all day and drank a little water at night. But while they were taking their rest, a great serpent from the nearby forest appeared before them and hungrily began to swallow up Nanda Maharaja. Nanda began to cry helplessly, "My dear son, Krsna, please come and save me from this danger! This serpent is swallowing me!" When Nanda Maharaja cried for help, all the cowherd men got up and saw what was happening. They immediately took up burning logs and began to beat the snake to kill it. But in spite of being beaten with burning logs, the serpent was not about to give up swallowing Nanda Maharaja.
At that time Krsna appeared on the scene and touched the serpent with His lotus feet. Immediately upon being touched by the lotus feet of Krsna, the serpent shed its reptilian body and appeared as a very beautiful demigod named Vidyadhara. His bodily features were so beautiful that he appeared to be worshipable. There was a luster and effulgence emanating from his body, and he was garlanded with a gold necklace. He offered obeisances to Lord Krsna and stood before Him with great humility. Krsna then asked the demigod, "You appear to be a very nice demigod and to be favored by the goddess of fortune. How is it that you performed such abominable activities, and how did you get the body of a serpent?" The demigod then began to narrate the story of his previous life.
"My dear Lord," he said, "in my previous life I was named Vidyadhara and I was known all over the world for my beauty. Because I was a celebrated personality, I used to travel all over in my airplane. While traveling, I saw a great sage named Angira. He was very ugly, and because I was very proud of my beauty, I laughed at him. Due to this sinful action, I was condemned by the great sage to assume the form of a serpent."
One should note here that before being favored by Krsna, a person is always under the modes of material nature, however elevated he may be materially. Vidyadhara was a materially elevated demigod, and he was very beautiful. He also held a great material position and was able to travel all over by airplane. Yet he was condemned to become a serpent in his next life. Any materially elevated person can be condemned to an abominable species of life if he is not careful. It is a misconception that after reaching the human body one is never degraded. Vidyadhara himself states that even though he was a demigod, he was condemned to become a serpent. But because he was touched by the lotus feet of Krsna, he immediately came to Krsna consciousness. He admitted however, that in his previous life he was actually sinful. A Krsna conscious person knows that he is always the servant of the servant of Krsna; he is most insignificant, and whatever good he does is by the grace of Krsna and the spiritual master.
The demigod Vidyadhara continued to speak to Sri Krsna. "Because I was very proud of the exquisite beauty of my body," he said, "I derided the ugly features of the great sage Angira. He cursed me for my sin, and I became a snake. Now I consider that this curse by the sage was not at all a curse; it was a great benediction for me. Had he not cursed me, I would not have assumed the body of a serpent and would not have been kicked by Your lotus feet and thus freed from all material contamination."
Krsna Book, Chapter 34
"'Being touched by the lotus feet of Sri Krsna, that serpent was immediately freed from the reactions of his sinful life. Thus the serpent gave up his body and assumed the body of a beautiful Vidyadhara demigod.'"
Purport: This is a quotation from Srimad-Bhagavatam (10.34.9). The inhabitants of Vrndavana, under the leadership of Nanda Maharaja, once wanted to go to the bank of the Sarasvati on a pilgrimage. Nanda Maharaja was fasting, and he lay down near the forest. At that time a serpent, who was formerly cursed by Angirasa Rsi, appeared. This serpent had formerly been named Sudarsana, and he had belonged to the Gandharvaloka planet. However, because he joked with the rsi, he was condemned to take on the body of a big snake. When this serpent attacked Nanda Maharaja, Nanda Maharaja began to call, "Krsna! Help!" Krsna immediately appeared and began to kick the serpent with His lotus feet. Due to being touched by the Lord's lotus feet, the serpent was immediately freed from the reactions of his sinful life. Being freed, he again assumed his original form of Sudarsana, the Gandharva."
Caitanya-caritamrta, Madyam Lila 25:77
Bhaktivedanta Book Trust. Excerpted from text and purport of HDG A.C. Bhaktivedanta Swami Srila Prabhupada.