In J.R.R. Tolkien’s legendarium, the tree-like shepherds are called Ents.
Ents are ancient, sentient beings who guard and care for the forests of Middle-earth. Their name comes from an Old English word meaning “giant,” and Tolkien’s portrayal draws on the longstanding tradition of personified or talking trees while giving the beings their own language, history, and culture.
The most prominent Ent is Treebeard, or Fangorn, who appears in The Two Towers. During the story, Merry and Pippin meet him in Fangorn Forest and help bring about the Ents’ attack on Isengard, the fortress controlled by Saruman. The Ents’ decision reflects their anger at Saruman’s destruction of trees.
Ents are sometimes confused with Huorns. Huorns are related, more mysterious tree-like beings, but Tolkien distinguishes them from the fully speaking and deliberative Ents. The Entwives, who cultivated gardens and fields, were separated from the Ents long before the events of The Lord of the Rings.