I know who the Poro king is

So at first I thought it was quite heinous to kill such a magnificent beast as the Poro king, but then I thought about it, and what if its not the actual Poro King, instead someone dressed as him?

It dawned on me, that the poro king makes a glorious entrance by falling from the sky Who else magnificently falls from the sky?

Therefore mantheon is the Poro king.