The Sewers Are Not Scary.

 In Batman: Arkham Asylum (2009), there is a certain mission in which you have to venture into the sewers to collect potentially magic plant spores to formulate and antidote to stop a nearly nude Poison Ivy and cure her of her largeness. Unfortunately the sewers here are the lair of the terrifying Killer Croc.

Villainous Man.

This section of the game is a masterclass in atmosphere and tension, with the ambience dropping out and being in silence with only your fear. When the Croc Jumps out of the water to chase you down that first time and you have no idea what to do, that is fear, even scarier than the Scarecrow missions. The fact you have to keep as silent as possible to keep him out of your face is also scary, because you don't know when he's going to appear. The things he says while underwater are truly chilling.

"Die!" - Killer Croc

Unfortunately, he jumps out at you about every 15-30 seconds (in my experience, at least), so the fear loses its hold on you after about the third chase, and you learn that you can just throw a Batarang at his shock collar to get rid of him the second he jumps out. after that it just becomes a tedious maze navigation level, which sucks because the horror is so well designed.