At the very end of Alien3, we meet a character (credited as Bishop II) who claims to be
the creator of the Bishop android.
He goes on to claim
that he is indeed human.
What confuses me is that he
is bleeding something that looks like blood after being hit on the head, but his ear seems to be pointing out at a very weird angle, that doesn't look like it was a type of injury a real person could have.
Here are some pictures to illustrate what I'm talking about:
According to the wiki page for Michael Bishop on
alienfilmspedia the question whether he's actually human or not is currently open.