Alright, so a bruiser, a spellcasterthief, and a sneak with spell potential (dude, just find a way to no-problem use silent spell, you're golden. Incantatrix, maybe?).
I know what character type I want, just have to make my choice. Working with this group is a child, adorable and seemingly harmless, and who is composed in character. He happens to be a dragon bent on destruction and death, but you can't really take his adorable form seriously.
I was thinking about pyroclastic dragon with the Deceivingly Innocent Form[Monstruous] feat. The flavor pre-req of consuming flesh of disguise, meaning a small child, should be easy considering he's a pyroclastic dragon. Alternatively, I also like the Silver dragon for it's speed, spellcasting, paralyzing breath, and deceptive lean. It means he can really get the most out of being sadistically manipulative and evil, while pyroclastic more lends itself to the psychotic destruction variety of killing.
Still, researching other dragons, just in case one jumps out at me. I know the red dragon is the classic, but realistically I could play something incredibly similar to that any time.
Not that I don't love the Iron Golem / Force Golem "Ironman" thing that could be going on, but an evil child? how do I pass that up?