ॐ देवी कालरात्र्यै नमः॥

Maa Kalratri is the Seventh form of Maa Durga, Kalratri is a furious form of Maa Durga, in this form she destroyed the most dangerous demons Shumbh and Nishumbha.

Mantra: करालवंदना धोरां मुक्तकेशी चतुर्भुजाम्। कालरात्रिं करालिंका दिव्यां विद्युतमाला विभूषिताम॥

Karalvadnam ghoram muktkeshi chaturbhjam. Kaal Ratrim karalikaam divyam vidyutmala vibhushitam.