Halloween presents a wonderful excuse for a lot of things, one of the best probably being the simulation of murder and suicide for the purpose of terrifying innocent children. It's a bit difficult to pull it off live, but if you're into the idea of making a festively gory flick, an air compressor blood cannon can go along way.
The concept here, as Shanks FX shows off, is quite similar to the tried and true tradition of using squibs with blood-spatter in films. The air compressor version, however, doesn't require explosives. Instead, you load up the compressor's hose with fake blood, and make sure you shoot (with a camera) the scene just right so the shot (with the gun) lines up with the blood. Simple.
Firing anything out an air compressor can be a little dangerous, so you might want to opt for plastic bag squibs, espeically for a live performace. But whatever you do, have a (fake) bloody Halloween. [Shanks FX]