ZombieHorrorShader

ZombieHorrorShader is a lightweight post-processing shader pack for Iris and OptiFine designed to turn your Minecraft world into a gritty, suspenseful zombie apocalypse.

Instead of requiring heavy custom resource packs or complex mod setups, this shader handles everything dynamically. It alters the game's colors to create a cold, desaturated, horror-movie aesthetic while automatically forcing the eyes of hostile and passive mobs to glow blood-red in the dark.

Features

Atmospheric Night Lighting: Deep shadows are lifted slightly with a cold, pale-blue "ambient moonlight." This keeps the night incredibly spooky and suspenseful while ensuring the terrain remains navigable and playable.
Sickly Movie Palette: The game's colors are desaturated and shifted toward a pale, greenish-grey tone. Warm lighting from torches, lanterns, and fire remains vibrant, creating a stark visual contrast.
Automatic Red Glowing Eyes: No resource packs required! The shader automatically isolates the eyes of key mobs and forces them to glow bright, emissive red in the dark:
- Zombies, Skeletons, Strays, Husks, Drowned, and Wither Skeletons
- Creepers
- Pigs, Cows, Sheep, and Chickens
Smart Pixel Targeting: The glowing eye feature uses model height and color-detection checks to ensure only the actual dark pupils of the mobs glow, preventing any red bleeding on their bodies, legs, or armor.
Vignette & Film Grain: A subtle, animated VHS-style film grain and a dark vignette frame the screen to create a claustrophobic, retro horror atmosphere.

Installation

Requirements

Iris Shader Loader (Fabric/Quilt) OR OptiFine (Forge/Vanilla).

Steps

Download the ZombieHorrorShader ZIP file.
Place the ZIP file inside your Minecraft directory's shaderpacks folder.
Launch Minecraft, open Options -> Video Settings -> Shaders.
Select ZombieHorrorShader and press Done.
Note: Ensure that your in-game brightness is adjusted to your liking to match the horror theme!

Performance

Because this shader operates purely on a lightweight post-processing and entity rendering pipeline, it has an incredibly minimal impact on performance (FPS), making it highly optimized for lower-end systems and large modpacks.
Compatible with standard vanilla and modded zombie entities from popular mods (such as Rotten Creatures, The Graveyard, Mutant Monsters, and Born in Chaos).

Zombie Horror Shader