The Megademons are one of Hell's most potent weapons. These archetypical demons are spawned from the hottest fires of Hell, with no other purpose than to act as a scourge to mortal souls. They are often found in conjunction with important tomes of evil, wicked artifacts, or guarding vital thoroughfares. At 12 feet tall, these creatures tower over their lesser kin, their leathery wings and treacherous horns making them an awesome sight to behold. Megademons are formiddable opponents, and attack without hesitation. Wielding jagged blades, they seek to hew the limbs from their victims and bring a bloody end to any who would oppose the might of their dark lords. Even disarmed, they are capable of inflicting serious damage with their razor-sharp claws and wings. But their most fearsome weapon is their hellish breath, with which they cook their opponents alive.
Megademons are found in the Caves and Hell levels of Diablo I. In this game, "Balrog" is the de facto name for the monster class, as well as a specific variant.