They are weak to Ice, so Blizzara spells will prove effective. Strago can also use Lv 4 Flare for heavy damage. A way of providing Vanish, such as the Esper Phantom, makes dealing with Behemoths easier, as their normal attack pattern is purely physical.
[view·edit·purge]Behemoth is a beast mentioned in Job 40:15–24. In addition to mythological creatures, it is likened to elephants, hippos, rhinos, and bison. Metaphorically, the term behemoth denotes "an extremely large or powerful entity."