Mahishasura is the great antagonist of one of Hinduism's central myths of divine power, the story that stands behind the autumn festival of Navaratri and Durga Puja. A shape-shifting asura (anti-god) who could take the form of a buffalo, he won through fierce austerities the boon that no man and no god could kill him, and, believing himself invulnerable, drove the gods from heaven and threw the cosmos into disorder. The gods' response is the myth's great innovation: unable to defeat him individually, they pool their energies (tejas), and from the combined radiance is born the warrior goddess Durga, a female power exceeding them all, mounted on a lion and bearing each god's weapon in her many hands.
Because the boon named only men and gods, a goddess falls outside its protection, and after a tremendous battle she slays him, the moment fixed in countless images as Mahishasuramardini, "the slayer of Mahishasura." The myth, given classic form in the Devi Mahatmya, is theologically pointed: it establishes the Goddess as the supreme power to whom even the gods must turn, and dramatizes the recurring principle that the overconfident boon carries within it the seed of its own undoing.