Mohini is the only female avatar of the Hindu God Vishnu. She is portrayed as an enchantress, who maddens lovers, sometimes leading them to their doom. Many different legends tell of her various exploits and marriages, including union with Lord Shiva.
Mohini also has an active history in the destruction of demons throughout Hindu texts. In the Vishnu Purana, Mohini defeats Bhasmasura, the “ash-demon”. Bhasmasura invokes God Shiva by performing severe penances. Lord Shiva, pleased with Bhasmasura, grants him the power to turn anyone into ashes by touching their head. The demon decides to try the power on Lord Shiva himself. Shiva runs terrified. Lord Vishnu, witnessing the unfortunate turn of events, transforms into Mohini and charms Bhasmasura. Bhasmasura is so taken by Mohini that he asks her to marry him. Mohini agrees, but only on the condition that Bhasmasura follows her move for move in a dance. In the course of the dance, she places her hand on her head. Bhasmasura mimics the action, and in turn, reduces himself to ashes.
After Lord Vishnu deceives the demons by his female form, Lord Shiva wishes to see the bewildering Mohini again. When Vishnu agrees and reveals his Mohini form, Lord Shiva runs crazily behind Mohini, while the abandoned wife Goddess Parvati looks on in shame and envy. Lord Shiva is overcome by Kama (love and desire).
Lord Shiva grabs Mohini’s hand and embraces her, but Mohini frees herself and runs further. Finally, Lord Shiva grabs her and their “violent coupling” leads to discharge of Lord Shiva’s seed. Lord Shiva impregnates Mohini, who gives birth to Lord Ayyappa. They abandon Ayyappa in shame.
The legend highlights Vishnu’s protests to be Mohini again and also notes that Ayyappa is born of Vishnu’s thigh as Mohini does not have a real womb. Another variant says that instead of a biological origin, Lord Ayyappa sprang from Shiva’s semen, which he ejaculated upon embracing Mohini. Lord Ayyappa is referred to as Hariharaputra, “the son of Vishnu (Hari) and Shiva (Hara)”, and grows up to be a great hero.