Goddess Kalratri, also known as Maa Kaali, is worshipped on Saptami, the seventh day of Navaratri. According to the most common legend, two demons Shumbha and Nishumbha invaded and defeated devlok (the realm of demigods). These demigods prayed to Goddess Parvati for help who readily transformed herself into Goddess Chandika, to battle with demons on behalf of all devtas. Goddess Chandika, also known as Chamunda, transformed herself into Goddess Kalratri and killed both these demons. Maa Kalratri fought another demon called Raktveej and kept drinking his blood till he was completely dead, causing her tongue to appear blood-red.