Yes, I got the quest, but no live (or undead) being is on Black Meadow map at the moment... I'm going to search again; the monster I killed was a forest lurker.
I killed The Dweller during the quest "The Smith's Shipment" before getting possession of Caed Nua and rebuilding The Warden's Hut. The head of The Dweller was not in the loot and now it is impossible to complete the bounty task.