The scratch was enough. Dean knew how this worked. It felt disgusting, the dead hand grasping and tearing his skin. It felt cold, the smell of the zombies was almost unbearable, and the worst part was the knowing that that was how this thing moved. That sooner or later, there'd be no stopping it from turning him into one of them.
Dean drew himself up straight and punched the zombie that scratched him right in the face. He saw part of the jaw come out the side of the thing's cheek as he hit it.
In another second, he heard a very alive-sounding, very annoyed, "OW! YOU SONOFABITCH!"