Imps

Imps are small, flying, intelligent monsters found only in the Ultima Underworld games. They fight by throwing magical bolts. In one instance an imp assisted the Avatar in his quest to defeat the wizard Tyball by providing him with a magical crown which helped the Avatar navigate an otherwise invisible maze in the Stygian Abyss. When the Guardian encased Castle British in a black rock gem, an imp spied on the Castle's inhabitants on the Guardian's behalf.

Lore
''These damnable abominations, virtually extinct elsewhere in Britannia, remain alive in the Abyss despite our best efforts to slay every last one of them. They are a foul conglomeration, part demon, part monkey and perhaps part creature or creatures unknown (to account for their hideous green coloring). Flying lazily overhead in the larger crevices, taunting our Knights and tossing down the occasional arcane bolt, Imps have been a nuisance and a thorn in our flesh since our arrival. They are poor fighters when one can draw them into hand-to-hand combat, and can easily be slain with a sword-thrust or two - if they can be enticed to fight.''

- from "Memoirs of Cabirus", Ultima Underworld