Angalamman is a manifestation of Goddess Parvati. This manifestation of Mother Goddess is more popular in South India.This is a fierce form of Goddess Shakti and she is also a guardian deity in many villages. It is stated that Goddess Parvati took the form of Angala Amman to help Shiva rid of the Kapala that was following Him after He cut off the fifth head of Brahma. Legend has it that Shiva took the form of Bhairava and cut off the fifth head of Brahma for being arrogant about His creation. Brahma had no remorse about the suffering that living beings had on earth.But soon Shiva felt remorse and for redemption of the sin, Brahma asked Shiva to become a wandering ascetic (Bhikshatana) and beg for food in a skull. As per the story of Angalamman, the fifth head started following Shiva. The head made his home in the arm of Shiva and started eating whatever Shiva received from begging. Goddess Parvati decided to put an end to the Kapala. On advice of Vishnu, she prepared food for Shiva at Thandakarunyam Tirth near Angikula Tirtham. Shiva came to eat the food. Goddess Parvati intentionally scattered food around the place and Kapala came down to eat them leaving the hand of Shiva. Goddess Parvati ceased this opportunity and took the fierce form of Angalamman and stamped down the Kapala using her right leg. (Source : wikipedia)