Duergar (DEW-ur-gar)

Duergar, also known as gray dwarves, or underdwarves are a subterranean subrace of dwarves. They carve out an existence in the Underdark, often near volcanoes. Their kinship to other dwarven subraces could be compared to that of the drow to surface elves.
Like other dwarves, duergar are typically thick, stocky figures, though beyond this there are many differences. Both male and female duergar are typically bald, with females also lacking the capacity to grow facial hair. Many are also thinner than their dwarven brethren. Most obvious, however, is their dull gray skin and hair, often matched with an equally stolid expression. Regular dwarves say they have flat heads, possibly as an insult. Because many duergar found on the surface world are criminal exiles, a surface dweller who encounters one of the gray dwarves is likely to notice facial and arm tattoos that mark the duergar as a traitor to his or her people.