Sometimes these are hard to find but usually you can get your hands on one at Halloween time.
Freaky Body Illusions has about a dozen or so effects that are all creepy and perfect for Halloween. My favorite is the brain flossing. When I saw the original demo I did not know how it was done, all the other effects I had pretty much seen before but the brain flossing was new.
This is in kit form, some of the effects have to be constructed (the box is the biggest and takes about five minutes, it goes together like tinkertoys but once completed is surprisingly sturdy).
These sell well for Abbott's at Halloween and even throughout the year (when they are available). Not high quality but perfect for Trick or Treaters at Halloween. Several of the illusions you have to watch your angles and some require special gloves (which are supplied). Comes with both DVD and written instructions which is really a bonus these days, nothing worse than having to find a DVD player or computer while practicing because you forgot something.
I like the brain flossing, the living arm, the bone breaker noise maker, and several of the box effects. I didn't care for the stretchy ear or the twisting of the head but that's just my opinion (to be honest I never even tried the ear, I saw the demo for it and didn't really understand what was happening).