As it is the first boss before equipment or items can be bought, defeating it is merely a matter of attacking it and hoping that the player's attacks do not miss.
It has three phases. After losing some health its horns and fangs are cleaved off, and is eventually having its face contorted with fury.
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."
In the German release, the Behemoth is called "Torros," which is based on the Spanish word toros meaning "bullfighting," in reference to its bull-like appearance.