J.R.R. Tolkien called the Ents “tree-shepherds” in The Lord of the Rings.
Ents are ancient, tree-like beings who tend and protect the forests of Middle-earth. Their name comes from an Old English word meaning “giant,” and Tolkien connected them to the long tradition of talking or sentient trees in European literature and mythology.
The most prominent Ent is Treebeard, who meets Merry and Pippin in Fangorn Forest. Their encounter helps awaken the Ents to the destruction caused by Saruman’s forces. The Ents subsequently march on Isengard in what is called the Entmoot’s decision and attack Saruman’s stronghold.
Entwives are a related but distinct group. Tolkien states that the Entwives were separated from the Ents after their gardens were destroyed, and their eventual fate is left uncertain. This is why Ents should not be treated as ordinary trees or confused with the Huorns, another mysterious forest-dwelling group.