J.R.R. Tolkien calls the tree-herding beings of Middle-earth Ents.
The Ents appear prominently in The Lord of the Rings, where they live in Fangorn Forest. They resemble walking, speaking trees and are led by Treebeard, one of the oldest living beings in the story. Their name comes from an Old English word meaning giant or being.
The Ents take action against Saruman after learning how his industrial activity is destroying Fangorn and its surrounding lands. Their assault on Isengard is one of the major turning points of the War of the Ring, and it helps remove Saruman’s power.
Ents are related to, but distinct from, Huorns, which are more tree-like and less openly person-like. Tolkien also describes Entwives, who tended gardens in a more cultivated landscape. The Entwives disappear before the events of The Lord of the Rings, and their fate is left uncertain.