City of Heroes/Nightmare Fuel


 * The original version of the "Dark Astoria" zone in City of Heroes: Permanently twilit and fog-enshrouded, with the sounds of muted bells and wind in the background, and populated by ghostly pedestrians who are visible only from a distance and vanish if you get too close to them -- except for the items they're carrying. (It also doesn't help that Astoria's neighborhoods and landmarks are named for horror movie directors.) Compared to the environment, the walking dead, evil shamans and malevolent spirits inhabiting Dark Astoria are something of a welcome relief.
 * Around 2010 Dark Astoria was reworked into a major endgame zone with Incarnate-level threats and missions. Sadly in the process it lost the fog and and the spectral pedestrians, and even though it's far more dangerous it's a whole lot less creepy.
 * Not running into the gigantic zombie outta nowhere though.
 * The Croatoa zone itself isn't that frightening (it's rather beautiful, for a pixellated environment). Some of the instanced missions within the zone are another story. Mainly the ones involving the ghosts, which look like floating, green-glowing, slightly zombified people who as their attack shoot several black, glowing skulls at you. And especially instances with the "spectral chill" fog, that you can't see through, and which lowers your combat capabilities.
 * For a real nightmare moment, turn up your sound enough to hear the death sounds for the Croatoa Ghosts. When they snuff it they make bloodcurdling screams of dying agony.
 * The screams made by defeated female members of the Carnival of Shadows are just as disturbing, but the animated departure of the spirits possessing them at the same time cranks the creep factor Up to Eleven.