Derro

Derro is the general name given to the degenerate humanoid creatures that inhabit the tunnels of the Underdark beneath Tolhera. They are small, violent and hate-filled creatures, with an aversion to light and a taste for mortal flesh. It is generally believed that they are made up of a mixture of races, whose people fled to the Underdark during the Schism and / or AngelDeath, the Calamity War. They only pose a threat to animals or children, but in groups are known to be fairly dangerous, though they rarely leave their tunnels. They are also often kept as slaves or servants by Drow and Duergar.

Derro is also a fairly common insult in the The Empire, meaning someone who is useless, ugly, and incapable of anything.