Once, when Kṛṣṇa and Balarāma were playing on the bank of the Yamunā, a demon of the name Vatsāsura assumed the shape of a calf and came there intending to kill the brothers. By taking the shape of a calf, the demon could mingle with the other calves. Kṛṣṇa, however, specifically noticed this, and He immediately alerted Balarāma about the entrance of the demon. Both brothers then silently approached him. Kṛṣṇa caught hold of the demon-calf by the two hind legs and tail, whipped him around very forcibly and threw him up into a tree. The demon lost his life and fell down from the top of the tree to the ground. When the demon lay dead on the ground, all the playmates of Kṛṣṇa congratulated Him, "Well done! Well done!" and the demigods in the sky showered flowers with great satisfaction. In this way, the maintainers of the complete creation, Kṛṣṇa and Balarāma, used to take care of the calves every day, beginning in the morning, and thus They enjoyed Their childhood pastimes as cowherd boys in Vṛndāvana.
One day, all the cowherd boys went to the bank of the river Yamunā to water their calves. When the calves drank water from the Yamunā, the boys also drank. After drinking, when they were sitting on the bank of the river, they saw a huge animal which looked something like a heron and was as big as a hill. Its top was as strong as a thunderbolt. When they saw that unusual animal, they became afraid of it. The name of this beast was Bakāsura, and he was a friend of Kaṁsa's. He appeared on the scene suddenly and immediately attacked Kṛṣṇa with his pointed, sharp beak and quickly swallowed Him up. When Kṛṣṇa was thus swallowed, all the boys, headed by Balarāma, became almost breathless, as if they had died. But when the Bakāsura demon was swallowing up Kṛṣṇa, he felt a burning, fiery sensation in his throat. This was due to the glowing effulgence of Kṛṣṇa. The demon quickly threw Kṛṣṇa up and tried to kill Him by pinching Him in his beak. Bakāsura did not know that although Kṛṣṇa was playing the part of a child of Nanda Mahārāja, He was still the original father of Lord Brahmā, the creator of the universe. Mother Yaśodā’s child, who is the reservoir of pleasure for the demigods and who is the maintainer of saintly persons, caught hold of the great gigantic heron by the two halves of his beak and, before His cowherd boyfriends, bifurcated his mouth, just as a child very easily splits a blade of grass. From the sky, the denizens of the heavenly planets showered flowers like the mallikā, the most fragrant of all flowers, as a token of their congratulations. Accompanying the showers of flowers was a vibration of bugles, drums and conchshells.