Mbh 12.284.10a

"'Having said these words unto his spouse Uma who was dearer to him than his own life, the puissant Mahadeva created from his mouth a terrible Being whose very sight could make one's hair stand on its end. The blazing flames that emanated from his body rendered him exceedingly awful to behold. His arms were many in number and in each was a weapon that struck the beholder with fear. That Being, thus created, stood before the great god, with joined hands, and said, "What commands shall I have to accomplish?" Maheswara answered him, saying, "Go and destroy the Sacrifice of Daksha." Thus ordered, that Being of leonine prowess who had issued from the mouth of Mahadeva, desired to destroy the Sacrifice of Daksha, without putting forth all his energy and without the assistance of any one else, for dispelling the wrath of Uma. Urged by her wrath, the spouse of Maheswara, herself assuming a dreadful form that is known by the name Mahakali, proceeded in the company of that Being who had issued from Mahadeva's mouth, for witnessing with her own eyes the act of destruction which was her own (for it was she who had impelled her lord to accomplish it for her sake). That mighty Being then set out, having obtained the permission of Mahadeva and having bowed his head unto him. In energy, strength, and form, he resembled Maheswara himself who had created him. Indeed, he was the living embodiment of (Mahadeva's) wrath. Of immeasurable might and energy, and of immeasurable courage and prowess, he came to be called by the name of Virabhadra--that dispeller of the goddess's wrath. He then created from the pores of his body a large number of spirit chiefs known by the name of Raumyas. Those fierce bands of spirits, endued with terrible energy and prowess and resembling Rudra himself on that account, rushed with the force of thunder to that place where Daksha was making preparations for his sacrifice, impelled by the desire of destroying it.