Mbh 12.166.4d

' That being then, abandoning the form he had first assumed, took the shape of a sword of great splendour, highly polished, sharp-edged, risen like the all-destructive Being at the end of the Yuga. Then Brahman made over that sharp weapon to the blue-throated Rudra who has for the device on his banner the foremost of bulls, for enabling him to put down irreligion and sin. At this, the divine Rudra of immeasurable soul, praised by the great Rishis, took up that sword and assumed a different shape. Putting forth four arms, he became so tall that though standing on the earth he touched the very sun with his head. With eyes turned upwards and with every limb extended wide, he began to vomit flames of fire from his mouth. Assuming diverse complexions such as blue and white and red, wearing a black deer-skin studded with stars of gold, he bore on his forehead a third eye that resembled the sun in splendour. His two other eyes, one of which was black and the other tawny, shone very brightly. The divine Mahadeva, the bearer of the Sula, the tearer of Bhaga's eyes, taking up the sword whose splendour resembled that of the all-destructive Yuga fire, and wielding a large shield with three high bosses which looked like a mass of dark clouds adorned with flashes of lightning, began to perform diverse kinds of evolutions. Possessed of great prowess, he began to whirl the sword in the sky, desirous of an encounter. Loud were the roars he uttered, and awful the sound of his laughter. Indeed, O Bharata, the form then assumed by Rudra was exceedingly terrible. Hearing that Rudra had assumed that form for achieving fierce deeds, the Danavas, filled with joy, began to come towards him with great speed, showering huge rocks upon him as they came, and blazing brands of wood, and diverse kinds of terrible weapons made of iron and each endued with the sharpness of a razor.