I got busy building. I figured the demon heads to decorate the rim of the cauldron would take the most time so I started them first. The cauldron was started and I ended up building a frame out of rolled up newspaper, but as Halloween came closer and closer, I realized there wasn't any way I was going to finish. Once I had my realization, I put the cauldron aside and decided to at least finish a few of the heads.
This Instructable documents the results.
Step 1: Armature...
The rounded top of the head was made from a few sheets of newspaper crumpled up into a ball. For the eye sockets, I took a sheet of aluminum foil and pressed two ping pong balls into it to form the shape. The lower part of the head was made from more newspaper, and finally all of the newspaper was covered in aluminum foil. The different parts were all duct taped together into one uniform armature.