Nice. I like the highlighted areas around the chimneys. Usually I don't like highlighting but I think its appropriate in this case and looks good. I think he looks suitable beefy and atomically viable (no head poking out of his arse that I can see, etc). +rep
What have you thought base wise? Its quite a large one. If I may suggest some sort of ripper swarm/tyranid ichor slime pool. Unless it wouldn't fit the rest of the army.