[1][2] According to the Sree Bhutanathaupakyanam, the Trimurti, composed of the deities Brahma, Vishnu, and Shiva, manifested itself in a single man known as Dattatreya, the son of a rishi known as Athri and his wife Anasuya.
When her husband decided to renounce the world, Leela protested, which caused the rishi to curse her to be born as Mahishi, a she-buffalo.
Satisfied by the impossibility of such an event, Mahishi, possessing the prowess of both the goddess of prosperity and power, quickly overran Svarga, taking the throne of Indra for herself and forcing the devas into exile.
Brahma arranged for Dattatreya to assume the form of Sundara Mahisha, a handsome bovine, who was able to enchant the lovestruck Mahishi enough to lead her away from heaven to the forests of Earth.
The devas beseeched Ayyappan to assist them in defeating her, and the child god ascended to heaven and caught the demoness by her horns and hurled her back to earth for her to die.