When the Goddess Parvati removed outer golden skin to kill demons named Shumbha and Nishumbha, She was known as Goddess Kalaratri. Kalaratri is the fiercest and the most ferocious form of Goddess Parvati.
is worshipped on the seventh day of Navratri.
Maa Kaalratri is treated as Guru of Planet Shani and governs it.
Goddess Kalaratri complexion is dark black and She rides on a donkey. She is depicted with four hands. Her right hands are in Abhaya and Varada Mudra and She carries sword and the deadly iron hook in her left hands.
या देवी सर्वभूतेषु माँ कालरात्रि रूपेण संस्थिता। नमस्तस्यै नमस्तस्यै नमस्तस्यै नमो नम: ।।