The ents: Language (p4)

The Elvish name for Ents is Onodrim, singular Onod.

Tolkien later noted that the destruction of Isengard by the Ents was based on his disappointment in Macbeth; when "Birnham Wood is come to castle Dunsinane", Tolkien was less than thrilled that it amounted to men walking on stage with leaves in their hats. He decided that when he did that scene for himself, he'd do it right.