Darklings

Over a millennium ago, the Darklings infested Xaria like a disease. Some
 thought they came from Drow experimentation, others that they were 
offspring of Goblins and Demons. Surface Elves saw them as a blight on 
nature and fought to remove them. They were successful and the Darklings
 retreated deep underground. However, with the recent departure of many 
of Xaria’s elves, the Darklings have chosen now to resurface. They seek 
to steal the life force and magikal items of man as parasites. All 
Darklings have a natural fear of elves and will avoid them unless they 
vastly out number them.
Complaint by villager on the outskirts of a Quiveran town to a Quiveran Army Officer:
“I don’t know what they were. I just don’t know. Like I said, I was 
chopping wood out back when I heard my wife scream. She was walking 
little Jebby down by the crick as she does every evening ‘round that 
time. I ran hard and found her cradling my boy and sobbing. No he wasn’t
 dead, thank Auberick. But he sure was sickly. Then I saw them. For only
 a moment, they looked at me with their cold black eyes then they just 
disappeared. I had turned to my wife for a second they just couldn’t 
have hid so fast. No, I told you, they weren’t goblins nor barbarians, 
nor the drow. I just don’t know what they were. Jebby’s recovered fine 
over the last week, but that don’t matter. You got to send out a patrol 
in the those woods and find those black devils.”