A term used occasionally the describe the Ent Treebeard of Fangorn Forest. Elsewhere described as 'Eldest', Treebeard was the oldest of the Ents still extant at the end of the Third Age (and thus may have been the first of that race to be created, though the details of the origins of the Ents are murky).

From his own account, Treebeard remembered the lands beyond the Blue Mountains before their destruction at the end of the First Age, making him at least six thousand years old at the time of the War of the Ring. Our earliest hints of the making of the Ents go back much farther than that, however, and they are first mentioned in a time before even the awakening of the Elves. Potentially, then, the history of the Old Ent went back to the very dawn of living things in Middle-earth.