The Bhagavata Purana and Vishnu Purana tells the story of Prithu: King Vena, from the lineage of the pious Dhruva, was an evil king, who neglected Vedic rituals. Thus the rishis (sages) killed him, leaving the kingdom without an heir and in famine due to the anarchy of Vena. So, the sages churned Vena's body, out of which first appeared a dark dwarf hunter, a symbol of Vena's evil. He had coppery hair, red eyes & was of a short stature. As he was very meek, the sages asked him to Nishidha (sit). Hence, he was called Nishadha, the founder of a race having his name. Since the sins of Vena had gone away as the dwarf, the body was now pure. On further churning, Prithu emerged from right arm of the corpse. To end the famine by slaying the earth and getting her fruits, Prithu chased the earth (Prithvi) who fled as a cow.