The Leviathan monster species first introduced in Monster Hunter 3, are identified by their similar appearance to crocodiles. They are also known to survive in underwater conditions, while others throughout magma in volcanoes. Fighting one almost always involves underwater combat; a leviathan is always guaranteed at some point to retreat to the depths of the oceans or lakes. They are almost always more adept at fighting underwater, while most hunters are hindered by the liquids. Fighting one requires at least a modest proficiency in underwater fighting, and, barring any skill in that, a measure of luck to coax the Leviathan on land.
 Monster List
The word Leviathan is very distinctly found from the Old Testament, in the book of Job. Job is having a debate with God, who at one point challenges Job, asking Job whether he could pull the Leviathan in with a fishhook. The Leviathan was described to had scales like shields, left waves in the water that resembled long white hair, and could breath furious fire. Experts now believe that this section was poetic wording of the crocodile, which fits the description well. Developer of Monster Hunter Tri have seemed to somewhat live to the leviathan's description as a crocodile when designing their beasts.