Dark Hound

The Dark Hounds are apparitions attracted by the use of pyromancy, and destructive spells. These invisible hunters are said to be large soot-black war hounds with brass flanks and iron fangs. Entering the mortal world through flames, these monstrous creatures search out the one who summoned them, their scorching breath withering everything in their path as they close in on their prey. The smell of sulphur, broiling flesh, soot, and hot iron indicate their presence.

Source

 * Warhammer Fantasy RPG 2nd ED -- Realms of Sorcery (pg. 80).