As promised in an earlier post, here's the image of The Hangman. In case you couldn't tell, he's a bad guy :-)
And just for fun's sake, here's the "artist's description" I got from the client. I thought it was a pretty great description, it definitely made the job easier. He even included a couple of reference artworks to give me some ideas, which was nice.
As per his description, he wears the upper part of the bodysuit under any normal clothing (and would wear long sleeve shirts to accomplish that).
I am thinking maybe the smarmy overconfidence that Edward Norton displayed toward the end of Primal Fear for how he would look in the face (I would include a picture of what I am talking about, but as of yet cannot find any).
I also think that it might be a good idea to have a "plainclothes" version of him in the foreground, with the elongated, masked version in the background/behind him rising up (to give an idea of how he gets away with his "dual existence" to some extent). If that is not possible, perhaps an "action shot" of him sloughing off his regular clothes and elongating out might be cool. As for his clothing - I am thinking some sort of body-suit that can stretch with him (to a degree). His hands would remain ungloved (so that he can feel what he is doing, both in terms of being more capable and also the thrill he gets from it).
As for the mask, I think that a more elongated version of the one I have attached would be damn near perfect - and would give a chance to see the side that he doesn't display when he is hunting to really come through (since you can still see his eyes and mouth).