yep! dido to jiggy's response.
Reem or rheem is the word and it is definitely an ancient form of Ox or bovine animal. I think the ancient Orox that was hunted by Cesar is the animal referred to; it had large double curved horns that pointed dangerously to the forward; it was almost as large as an elephant--much larger than oxen today; it was famous for its ferocious and unyielding charge. It was a renowned feat to subdue one; it was considered intractable. They were not tamed by men. Passages where the bible uses the figure in prophesy refer to the coming of Christ to rescue his people from their enemies. If you know anything of of the star constellation of Tarus, the bull, that is an ancient depiction of the rheem. You might slap a bull on the rump and run away, but a rheem would plow through any barrier and nail you. It was, in antiquity, the most ferocious animal if antagonized. The prophetic passages where it occurs depend on that idea. Extinct now, it is known only in ancient literature and fossils.
God bless...DGB