Origin story
Bhagavathi is the mother goddess honoured across Kerala in her many forms — Bhadrakali, Durga, Kali and the countless village deities who protect the land and its people. The word itself is an honorific for the goddess, used for Saraswati, Lakshmi and Parvati alike.
Kerala temples of Bhagavathi often commemorate the fierce yet maternal forms of the goddess, as at Kodungallur and Chettikulangara. The lamp, the mirror and the spear are her customary symbols, and her festivals bring the whole village together in ritual, music and offering.
Source: Wikipedia: Bhagavati — https://en.wikipedia.org/wiki/Bhagavati