Post moments when your mind has been fucked up the ass by Valve.
The creepiest thing in my opinion is the Poison Zombie sounds.
At first you hear it and don't think much of it, just another enemy to add to your kill list.
But then, you hear it stalking you, the strained breathing, the moaning, the horrible agony the thing is.
You walk to a door, only to hear that horrible raspy breath.
You wonder what abomination of mankind that beast could be.
You open the door to see a carrier for horrible animals.
The pain the zombie feels is excrutiating, which is obvious by his screams and moans of agony.