Possessing the mysterious power to transform him-self into the form of a great black bear at will, Beorn, even in his mannish shape was immensely tall and strong. He lived on the banks of the Anduin river, and shunned the company of others, preferring instead the companionship of animals.

When Thorin & co. encountered and eventually befriended Beorn, they were amazed at the cleverness of his dogs who could walk upright and even serve at table. His sheep and horses were also exceeding intelligent and were treated by Beorn more as friends than as livestock. He possessed an unswerving hatred of the orcs and was mightily impressed by the slaying of the great goblin by Thorin's party. Beorn gave rest and shelter to the Dwarves and even loaned them ponies for their journey. At the battle of the five armies he fought on the side of the Men and Dwarves in his bear shape.