Largest European members of the genus Corvidae. About 25 inches long with a heavy  black bill and blue-black plumage, irridescent in sunlight. They are highly intelligent and show signs of having insight and problem-solving skills. Like other members of this family they can learn to speak.

The friendly Ravens of Erebor are seen in The HobbitBalin says that the ravens are wise birds, handing on their knowledge to their children. They have always been friends of Thror and his people, bringing them news in secret.Carc and his wife nested above the guard-chamber on Ravenhill and it was their son Roäc who brought Thorin and Company news and information before the Battle of Five Armies.

In some cultures ravens are seen as ominous, but Tolkien uses them as wise advisors, the way they are seen in Scandinavian mythology. The God Odin was said to have two ravens called Thought and Memory that perched upon his shoulders. The normal lifespan of a raven in our Primary World is about 15 years, though some have lived to 40. Roäc however, must have been around 153 years old at the time of the Quest of Erebor which indicates that, like the eagles, Tolkien's ravens have a special significance in Middle-Earth.

NOTE: Additional information from Cirdaneth
Encyclopedia entry originally written by Meladoreara