Is the Antichrist supposed to be a human or a demon?

In futurist interpretations of Revelation, is the Antichrist (or the "Beast from the Sea") considered an evil human, or a demon in human form? I've seen unsourced claims that he's supposed to be the son of Satan, birthed by a harlot who appeared to be a virgin (making him a half-demon?), or that he is Satan in human form (like a mockery of Christ). However, I can't find the biblical foundations of those ideas. Even if those specific ideas are incorrect, though, it doesn't confirm that he's supposed to be human. I guess another way to ask is, is the Antichrist a fallen angel (making him a demon), or a more recent creation/spawn/devotee of the Devil (making him maybe human, maybe a demon)?