/cgl/ - Cosplay & EGL

I want to cosplay comic-style Hellboy with a moveable jaw (I don't particularly mind if it ends up looking overly artificial like Robotman, just so long as it moves). I've gathered some reference pics on the right; although the mask is pictured I'd be making my own mask/helmet out of foam or whatever.
What's the best way to go about this? I looked at furry head construction (pictured right) but since those are typically much larger and covered in fabric I'm not sure that approach will work out well for HB. I've also seen masks that connect to the jaw but those typically only cover the front of the face.