a Headless Horseman Pumpkin (Decerebrate) Cookie would be an effective deterrent, or great for Halloween tricks. Or, you could re-flavor it as the tastes-so-good-your-head-explodes or some more clever phraseology. Maybe the Highlander Cookie....
combine that (stp arcane fusion?) with Fiery Discorporation for creepy villain suicide escapes. (Crash and Burn Cookie?)