Are you sure it shouldn't be read as "*I* am a *MAN*" punctuated by punching a robot in the gut a la Bearded Idiot from Superman At World's End?
Ah, that is another interpretation...
"I may not be human, but I am a man. It means I can't kill the Lord of the Nazgul. At least, not on my own. We'll need a woman... wait, was I supposed to talk about sexual desire here?"--- Redcrow
That is definitely a good one.
You might possibly need a Hobbit...then again, maybe a Vampire would do...the source material is mostly clear but does leave a bit of room for alternate interpretations.