The Witchwing are a group of black-plumaged harpies found residing around the Dry Hills in the northern area of the Barrens. They have been ravaging the Horde's caravan supplies.
The lieutenants of their group, the Witchwing Slayers, are a nasty bunch, but they lead some of the underlings in that area. They stand out from the rest by wearing some rings.
Their leader is the sister of a harpy named Bloodfeather, who was slain by Rexxar quite a while ago. Apparently, their attacks on the Horde caravans are revenge for her sister's death.
Some of them carry Blood Shards.