Behemoth
BE'HEMOTH, noun ]Heb. a beast or brute; from an Arabic vert, which signifies, to shut, to lie hid, to be dumb. In Eth.dumb.]
Authors are divided in opinion as to the animal intended in scripture by this name; some supposing it to be an ox, others, an elephant; and Bochart labors to prove it the hippopotamus, or river horse. The latter opinion is most probably. [See Hippopotamus.] The original word in Arabic signifies a brute or beast in general, especially a quadruped.
First Occurrence in the Bible(KJV): Job 40:15