While reading through Borges’ Seven Nights, I came across a reference in his discussion of the Kabbalah in which he mentions that “Behemoth” is actually plural, meaning “the animals.” Looking this up in the ever-reliable Wiktionary, I learned that

It may be an example of pluralis excellentiae, a Hebrew method of expressing greatness by pluralizing a noun; it thus indicates that Behemoth is the largest and most powerful animal.

Behemoth is so big that it has to be plural. Language is great.