Goodness boy! Learn your zombie lore x.x Most zombies are just the reanimated dead, not possessions. Possessions are a different thing all together. Even when dead, the brain still is the area firing the impulses through your body to move. Zombies are more often then not just creatures with the basic human functions, consume something for fuel to live. You destroy the one area that's sending the signals to move, to eat, to run, and it's dead. Even if a bacterium was the reason, it still needs the brain to send those impulses.

You're soooo gonna die in the zombocalypse, Hypo. NOW ENOUGH ABOUT ZOMBIES. This is what's scarier than them thread x.x