The balrog (BÁL-róg or BÄL-róg) the fiercest of the lesser daedra. While the first of their kind were sired by Revonos, who raped Lilith in order to produce them, the balrogs now reproduce on their own and serve as the front-line troops in the war between the gods and daedra lords. They most often appear as enormous black minotaur-like beings with huge dragon-like wings.
Balrogs cannot cast spells, but they are frightfully strong and incredibly nasty. Their skin is extremely tough, and only a few types of weapons (notably blessed or highly enchanted weapons, Elven steel, and mithril) can hurt them. They can also be hurt by magic, but their resistance to magical heat and cold is very high. The best thing you can do if you see a balrog is to start running.