Hobgoblins

No one knows for sure who created the first Hobgoblin. Some say it was Shazaar, the Cryptarch who first crossed Humans and Goblins. Some say it was the Elves. After The Hubric Wars, hobgoblins fled to the Underdark. There they serve as generals and leaders to different goblin and duergar clans.
For the past few hundred years, the elves have used hobgoblins as slaves. It is one of those things people just ignore, as hobgoblins are generally evil. However, very little people know that the entire island of Meiyurai is populated by hobgoblins who are slaves to the elves. The elves have trained hobgoblins to supplement their army, with entire battalions of hobgoblins. They also have forced the hobgoblins to mine for them. Massive mine shafts go down into the Underdark on Meiyurai and even tunnel under Niphon.