SCP-966, Slender Fortress Wiki

SCP-966 also known as The Sleep Killer is a boss on Slender Fortress. SCP-966 is a monster that can only be seen through night vision or infrared devices, it looks like a tall lanky humanoid with an alien like face with a boney head, long sharp claws, greyish skin that looks like it is tightly wrapped on the entity and outstretched limbs, they are extremely slow in containment breach and takes up to 30 hits to kill the player and can appear anywhere in the facility after you encounter their cont

SCP-966, SCP: Devolved Wiki

SCP-106, Slender Fortress Wiki

SCP-966, Site Delta Wiki

SCP-966 Sleep Killer Euclid [SCP Document Reading]

Invisibility Superpower+BreezeWiki

SCP-966 Villains+BreezeWiki

Steam Workshop::SCP-966

Steam Workshop::Orion Network's SCP-RP Content

SCP Animated: Tales from the Foundation Sleep Killer (SCP-966) (TV Episode 2021) - IMDb