I love halloween! I have a big lolly jar, that has a neck that's only big enuff for a kids hand to go in, but not big enuff for them to pull it out again when they get a fist full of lollies...... muahahhahahaha!!!!
Check this out. There's heaps of things that look LIKE the monster you have to spot, but he's not hiding where you think! This does need sound on, and crank it up loud - good sound effects!
http://www.worldschoolphotographs.com/halloween.htm 