[DannyK]

try a search for scissors mechanisms and possibly use the pneumatics from the posts about MIB's and such...use a cylinder to pop the lid and another on a wig head with a cool mask on it. Google prop-1 and prop-2 if you want a decent controller. it will take a bit of learning on your part, but I think what you have in mind could turn out to be a really creepy prop.

hope I helped somewhat...off to watch the fight!!

-DK