This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Behemoth (Jewish)
Behemoth is a beast from the biblical Book of Job, and is a form of the primeval chaos-monster created by God at the beginning of creation; he is paired with the other chaos-monster, Leviathan, and according to later Jewish tradition both would become food for the righteous at the end-time. Metaphorically, the name has come to be used for any extremely large or powerful entity.
In Jewish apocrypha and pseudepigrapha, such as the 2nd century BC Book of Enoch, Behemoth is the unconquerable male land-monster, living in an invisible desert (Duidain) east of the Garden of Eden, as Leviathan is the primeval female sea-monster, dwelling in "the Abyss", and Ziz the primordial sky-monster.