Some say, behemoth and leviathan are dinosaurs. This is heresy and nonsense.
According to Strong’s, “behemoth”, בַּהֲמוֹת (b’hemot), h930, is the water ox, otherwise known as the hippopotamus or the Nile-horse. In modern Hebrew, a hippopotamus is הִיפּוֹפּוֹטָם (hipopotam), or סוּס יְאוֹר (sus y’or), or בְּהֵמוֹת (b’hemot). So it is beyond doubt that a behemoth is a hippopotamus.
According to Strong’s, “leviathan”, לִוְיָתָן (livyatan), h3882, is a serpent, particularly the crocodile or some large sea monster, and figuratively also the constellation of the dragon and a symbol of Babylon. In modern Hebrew, a crocodile is תַּנִּין (tanin).
If behemoth in Job 40 is a hippopotamus, then surely leviathan in Job 41 can be thought of as a crocodile, putting aside for a moment the bits that mention fire breathing, Job 41:19-21; because as animals in nature, both the hippopotamus and the crocodile live in a river, and one contrasts the other. The hippopotamus is a herbivore; the crocodile is a carnivore. The hippopotamus eats placidly; the crocodile eats frenziedly. The hippopotamus is a warm blooded mammal; the crocodile is a cold blooded reptile.
Occasionally, a hippopotamus and a crocodile will fight. In a full on fight, the crocodile is no match for the hippopotamus.
This explains why, almost always a crocodile will back away when a hippopotamus approaches.
Job 40:19 suggests behemoth is a metaphor for the LORD.
“He is the chief of the ways of God: he that made him can make his sword to approach unto him.”
– Job 40:19
Job 41:10, Job 41:34 and Isaiah 27:1, when considered together, make it clear that leviathan is a metaphor for Satan.
“He beholdeth all high things: he is a king over all the children of pride.”
– Job 41:34
“None is so fierce that dare stir him up: who then is able to stand before me?”
– Job 41:10
It is perhaps not a coincidence that the first god of the ancient Aztecs, the people who practised ritual blood sacrifice atop pyramid temples, was Cipactli, a deity in the form of a crocodile.
Incidentally, in the Jewish Tanakh, the passages on leviathan are partly in Job 40 and partly in Job 41, so the contrast between behemoth and leviathan is not there, and the point is not as clear.
Anyway, given the 2 metaphors, it is quite fitting that in nature in a fight between a fully grown hippopotamus and a fully grown crocodile, the hippopotamus always prevails!