Looking for Lakshmi, Vishnu sits in an anthill on the Venkata hill, and Brahma and Shiva come as a cow and calf to feed him. The Chola king's cowherd, finding the cow dry, follows her and swings his axe; the god rises from the anthill and takes the blow. The wound on his head is why the image wears camphor, and why pilgrims give their hair.
Vishnu, unable to find Lakshmi after Bhrigu's kick, takes an anthill under a tamarind by the pool on the Venkata hill for a home. Brahma and Shiva pity him and become a cow and her calf, and Surya tells Lakshmi, who as a cowherd woman sells them to the Chola king. The cow grazes on the hill with the royal herd and every day empties her udder into the anthill. The queen notices she gives no milk and scolds the cowherd, who follows her, sees the milk running into the mound and swings his axe at her. The Lord rises from the anthill and takes the blow; the cowherd, seeing him bleed, falls dead. The cow runs bellowing back to the palace with blood on her; the king follows, and is cursed for his servant's act, the curse to end when, born again as Akasha Raja, he gives his daughter Padmavati to the Lord.
The axe took away a patch of hair, the pilgrims say, and it would not grow back. A Gandharva princess, Neela Devi, saw it as the god slept and cut off her own hair and set it on his head. When he woke he wanted to give it back. She said that whoever came to his hill and gave him their hair would be giving it to her, and that would be enough. So the barbers' halls at Tirumala never close, and the camphor on the image's chin, others say, is for the wound.