Anyway, I finally got around to forming the basic shape of the head with steel rods (mostly scraps from old cooling racks) and some pieces of sheet metal and other odds and ends. I've got the protruding teeth roughed out (the mouth will be closed) and I've got a framework for the mandible. The mandible isn't attached to the head yet and the head isn't attached to the body because it's still easier to work on them with the ability to turn them upside down, etc.
I'm pretty happy with the way this is turning out. I've got plenty of bendable steel rod to form the rest of the contours, but I'm starting to run short on interesting sheet metal. Tomorrow is a "machine comes along and scrapes up everyone's curb trash piles" day in Columbia, though, so I may spend the morning scouting around for some interesting scrap so I can finish this thing soon.