Okon Tengri, the 'Maiden Heaven', is the great goddess of the Kalmyks, a figure in which an older shamanic fire-deity and the Tibeto-Buddhist protectress Palden Lhamo (Shridevi) have merged. In her archaic aspect she is the goddess of the hearth and of the sacrificial fire invoked in clan rituals; in her Buddhist aspect she is a fierce dharmapala who rides across the sky as guardian of the faith and of the Kalmyk nation, and her festival opens the spring with the White Month. A widely told myth casts her as a redemptive and terrible figure who sacrifices herself to a devouring monster, bears its child, and then destroys the beast by breaking open the iron casket that holds its external soul. In popular devotion her name is sometimes used interchangeably with those of Palden Lhamo and White Tara. Sources differ on whether her fire-goddess character is the original core later clothed in Buddhist iconography, or an indigenous reading of an imported protector.