In the Yamuna near Vrindavan was a deep pool where the poisonous serpent Kaliya lived. His venom had turned that stretch of water black. Cows and cowherd boys who drank it fell ill.
One day, while playing, Krishna’s friends and the cows drank that water and fell unconscious. Seeing this, Krishna felt the river’s poison was harming Gokul. He jumped into the Yamuna from a kadamba tree.
Kaliya coiled around Krishna and held him tight. The people of Braj were distraught on the bank. Then Krishna enlarged himself and Kaliya’s grip loosened. He climbed onto the serpent’s hoods and began to dance.
Tired from the weight of the dance, Kaliya begged forgiveness, and his wives also prayed to Krishna. Krishna ordered him to leave the Yamuna with his family and go elsewhere, so the water could be pure again.
As soon as Kaliya left, the Yamuna’s water became clear again. The people of Braj hugged little Krishna. In tradition this episode shows that fear and evil should be faced with courage and humility.