Domesticated Goblins
For centuries, the Goblins have been a favorite species among slave owners. They breed like rabbits and their natural frailty and stupidty makes them easy to control (well, we use "control" loosely here. They're still Goblins). Because of this, they are essentially the 'made in china" of slave labor. Cheap and easy to get. It is rare to find Domesticated Goblins in the homes of the rich Elves, who prefer more aesthetically pleasing, exotic slaves. But Domesticated Goblins are often seen alongside Orcs in the streets of <elf place> keeping the cities sparkling clean. But mainly they are the ones sent to clean the sewers, and do other things that require small body and are generally unpleasant. They are not sent to the mines though. Way to many shiny things. That's left to Orcs, Dwarves, and other big, tough things.
Encompassed species