Big Black Crows with pointy teeth.
Turbine has posted more creature information for Lord of the Rings Online: Shadows of Angmar. The creature of choice today is the Crebain. There is a fair to slim chance that they wrote this:
"These menacing black birds from the lands between the Misty Mountains and the dark forest of Fangorn are often controlled by the forces of darkness, acting from above as the eyes and ears of the enemy. Large and intelligent, flocks of these crow-like creatures darken the skies on their mission of evil. But be warned – even one Craban is capable of alerting the enemy with the swiftness of the wind. "
You can read the entire Lord of the Rings Online: Shadows of Angmar - Creban Article at the Official Site.