He's a monster! This is easily the creepiest picture that you ever worked on. What makes it so effective is that there really isn't anything supernatural about this guy's appearance, he's just very disgusting looking. I'm glad all old people don't look like that. The shading was wonderfully done in this. I think my favorite thing is how well you managed to get the vessels in his head. There really is a rainbow of colors here. In the background, it looks like there's green gas or something, like a fart, maybe?
I appreciated how villianous he looks in this. He doesn't even look human at times, he looks more like a crow like creature. It seems like every old person with a big nose looks like that. I like how his Adam's Apple is sort of just sticking out, like some smooth object. You know how to put atmosphere in your work.