See Graham for the Human & Bear figures of Beorn

Beorn is a character created by J. R. R. Tolkien, and part of his Middle-earthlegendarium. He appears as a "skin-changer", a man who could assume the form of a great black bear. His descendants or kinsmen, a group of Men known as the Beornings, dwell in the upper Vales of Anduin, between Mirkwood and the Misty Mountains and are counted among the Free Peoples of Middle-earth who oppose Sauron's forces during the War of the Ring. Beorn exemplifies the Northern courage.

Beorn lives in a wooden house on his pasture-lands between the Misty Mountains and Mirkwood, to the east of the Anduin. His household includes an animal retinue (with horses, dogs, sheep, and cows); according to Gandalf, Beorn does not eat his cattle, nor hunt wild animals. He grows large areas of clover for his bees. Gandalf believes that Beorn is either a descendant of the bears who had lived in the Misty Mountains before the arrival of the giants, or a descendant of the men who had lived in the region before the arrival of the dragons or Orcs from the north.
 

He is of immense size and strength for a man and retains these attributes in bear-form. He has black hair (in either form) and a thick black beard and broad shoulders. While not a "giant" outright, Beorn's human form is of such great size that the three and a half foot tall Bilbo judges that he could have easily walked between Beorn's legs without touching his body. When Bilbo meets him, Beorn has "great bare arms and legs with knotted muscles" and wears "a tunic of wool down to his knees. Beorn names the large rock by the River Anduin the Carrock; he had created the steps that led from its base to its flat top.