Item aquired in the Dead Man's Hand Instance.
Was vaguely explained by Silirrion on March 21, 2012:
"It might be another teaser for the next Adventure Pack ... Keep the Dead Bird!"
Dead Bird launches a quest Black Ring Raven to find the owner of the bird. The Black Ring Sorcerer can be found in Dragon's Spine in a cave near Excavation Site.
- Reward: Pet: Stygian Sand Hawk