If there were a true beast king, Malar would more likely be it.
However Malar, though a god in existance longer than Xvim, was less powerful, due to the fact he had no humanoid followers... which indeed determines a god's status.

Malar was a beast's god... The god of savagery. He himself created and changed creatures over time, perfecting them and evolving them. His personal favourite beasts would be transformed with magic energy, making them ruthless killers.

However, for all this ability, Malar was easily subdued by the more powerful Xvim. But he vows it wont be for long...