Bhasmasura was born of the Bhasma dust (ashes) on the body of Lord Siva. Pleased with the great devotion of the demon, Siva asked him to name any wish. Bhasmasura said that he wanted the power to burn someone to ashes, simply by touching his hand to their head. Bhasmasura became abusive and arrogant, and created a nightmare for the whole world.
To answer the prayers of his devotees, Mahavishnu appeared to defeat Bhamasura in the form of Mohini, an mysterious dancer. Bhasmasura was taken with Mohini's beauty and agreed to learn a dance she called Muktanritya. This deity depicts the moment when Mohini Murti led the demon Bhasmasura to follow her motions and touch his own hand to his own head, causing him to burn to ashes.
Mohini-murti was also present at the churning of the Milk Ocean. When the demons got the nectar of immortality from the ocean, Mohini-murti took the jug away and gave it to the demigods. The only demon who got to taste the nectar was Rahu, but she cut his head off before the nectar went into his body. Thus, Rahu's head became a planet (node of the moon).
Another photo of my Mohini Murti. My father acquired this deity in India in 1978 and left it to me.