Balrons

Balrons  are a type of daemonic creature which appeared in old Sosaria and in early Britannia as it came out of the Age of Darkness. They are amongst the most formidable of the hellborn, and have been known to command legions of devils and other foul beings. They appear in Ultima I,  II,  III and  IV.

Description
The balron has been consistently described as having an appearance similar to other daemons - with a thick, leathery hide and wings upon which it may fly. What sets balrons apart from their lessers, however, has long been their mastery of the magic arts. Balrons are renowned for use of powerful spells on the battlefield, and have been observed hurling balls of fire and poison at their victims. The balrons' potent ability to mystically lull their foes into slumber is especially debilitating, as it leaves those who succumb to it vulnerable to further violence. During the the time of Minax's interference with Earth, artifacts known as green idols existed, which could be used to counteract this disastrous effect. Such devices, however, eventually ceased to become available, leaving explorers facing these creature to rely on the powers of certain potions or a well placed An Zu spell.

After their initial appearance in Ultima I, balrons appeared in Ultima II, Ultima III and Ultima IV, but seemingly faded from the material world as it moved into the Age of the Avatar. Although immensely powerful daemons such as the Slasher of Veils and Arcadion have still stuck with Britannia and its people, it remains unknown what has happened to the once populous balrons of old.

Trivia

 * Balrons are very likely inspired by the balrog, from J.R.R. Tolkien's classic Lord of the Rings trilogy. In the manual for the Nintendo Port of Ultima IV, the creatures are, in fact, referred to as balrogs, and an illustration of one closely resemble the leonine creature depicted in Ralph Bakshi's 1978 film adaptation of the books.
 * The FM-Towns Ultima Trilogy mistranslated the name of this creature throughout the games as "barlon." In the port of Ultima II, a "Pazuzu Barlon" appears. Pazuzu, in addition to being an archaic Bablyonian wind god, is well known for appearing as the demon which possesses Regan McNeil in the film The Exorcist.
 * The variant of balrons known as orcus derive their name from Orcus, the Etruscan and Roman God of the Underworld. This deity has frequently lent his name to fictional demons and may have been the inspiration for Tolkien's orcs.