Silent Hill - Did You Know Gaming? Feat. Two Best Friends Play (Matt & Pat)
18 years after the game's release, on September 16th 2017, a Silent Hill fan community member by the name of roocker666 posted images of never before seen enemies hidden in the game's files online. These formerly unseen creatures include a giant headless frog (FRG), a possibly monkey based creature (MKY), an ostrich like creature (OST), a purple moth (BTFY), a manta ray (El), and a faceless snake (SNK).

Three additional models were discovered at a later date, including beta versions of the Larval Stalker and the Grey Children, and most notably a giant chicken (CKN) that was bigger than the others and is thought to have been intended to be a boss character.

Masahiro Ito, the game's background and creature designer, acknowledged the discovery on Twitter, but had no comment regarding the original purpose of the models.
Contributed by Mass Distraction
In the North American version, the enemies known as "Grey Children" bare a strong resemblance to real-life children, however in the Japanese & European versions they were instead replaced by "Mumblers".
Contributed by ProtoSnake
NSFW - This trivia is considered "Not Safe for Work" - Click to Reveal
In the Silent Hill demo included in the Official U.S. PlayStation Magazine Demo Disc #16, there are a number unused early artwork and placeholder images found in the game's files. One of the placeholder images for the Options screen is of a group of Japanese women posing naked, and another for the Save/Load screen is of a naked woman laying on a hospital bed.
Contributed by KnowledgeBase
The word "RED RUM" can be found written in blood on a garage door on Bloch St. This is a reference to the Steven King novel The Shining.
Contributed by Boyobmas
Due to the lack of processing power on the PlayStation for an open-world map, the developers used the fog to allow the game to load objects as the player approached them.
Contributed by Stryker94
If you go into the final boss with no ammo for any of your weapons, the boss will die on it's own.
Contributed by gamemaster1991
Parts of Midwich Elementary School are based off Astoria Elementary School from the movie Kindergarten Cop.
Contributed by gamemaster1991