Mbh 12.282.1a

"'Bhishma said, "Listen, O king, to me as I tell thee the symptoms that appeared on the body of Vritra when he was overtaken by that fever (born of the energy of Mahadeva). The heroic Asura's mouth began to emit flames of fire. He became exceedingly pale. His body began to tremble all over. His breath became hard and thick. His hairs stood on end. His memory, O Bharata, issued out of his mouth in the form of a fierce, dreadful, and inauspicious jackal. Burning and blazing meteors fell on his right and left. Vultures and Kanakas and cranes, gathering together, uttered fierce cries, as they wheeled over Vritra's head. Then, in that encounter, Indra, adored by the gods, and armed with the thunderbolt, looked hard at the Daitya as the latter sat on his car. Possessed by that violent fever, the mighty Asura, O monarch, yawned and uttered inhuman cries.[1394] While the Asura was yawning Indra hurled his thunderbolt at him. Endued with exceedingly great energy and resembling the fire that destroys the creation at the end of the Yuga, that thunderbolt overthrew in a trice Vritra of gigantic form. Loud shouts were once more uttered by the gods on all sides when they beheld Vritra slain, O bull of Bharata's race! Having slain Vritra, Maghavat, that foe of the Danavas, possessed of great fame, entered heaven with that thunderbolt pervaded by Vishnu. Just then, O thou of Kuru's race, the sin of Brahmanicide (in her embodied form), fierce and awful and inspiring all the worlds with dread, issued out of the body of the slain Vritra. Of terrible teeth and awful, hideous for ugliness, and dark and tawny, with hair dishevelled, and dreadful eyes, O Bharata, with a garland of skulls round her neck, and looking like an (Atharvan) Incantation (in its embodied form), O bull of Bharata's race, covered all over with blood, and clad in rags and barks of trees, O thou of righteous soul, she came out of Vritra's body.