Nightmare Fuel / Outpost

http://static.tvtropes.org/pmwiki/pub/images/outpost_still01_7558.jpg
You can't kill what's already dead.
  • If fighting an undead elite SS unit wasn't scary enough... they can also become invisible and move through solid objects.
http://tvtropes.org/pmwiki/pmwiki.php/NightmareFuel/Outpost