Make your own tinfoil portraits/sculptures. You could buy face masks and give students tinfoil. I think this would work. Would probably look even better on a black canvas or cheaper option, black card.
Stephen: My name is Steve, and I am an industrial designer from NJ. I love designing and building a new halloween costume every year that challenges my skills and knowledge of. Super awesome cosplay of The Iron Giant
halloween makeup diy -- tutorial on how to create fake wounds that could be used for claw marks, demon attacks, zombie makeup or anything else you can dream of. a bit skimpy on details but it's a great start