To destroy demon Mahishasura, Goddess Parvati took the form of Goddess Katyayani. It was the most violent form of Goddess Parvati. In this form Goddess Parvati is also known as Warrior Goddess.
Goddess Katyayani is worshipped on the sixth day of Navratri.
It is believed that the planet Brihaspati is governed by Goddess Katyayani; whose Jupiter is not good in the horoscope they should worship Goddess Katyayani.
Goddess Katyayani rides on the magnificent lion and depicted with four hands. Goddess Katyayani carries lotus flower and sword in her right hands and keeps her left hands in Abhaya and Varada Mudras.