SCP-966 are predatory creatures that resemble hairless, digitigrade humans, possessing an elongated face with a mouth lined with needle-like teeth. Physically, they are weak, possessing hollow bones and low muscular density. They do not seem to rest through sleep; instead, they will suddenly cease all movement at seemingly random intervals of time, resuming normal activity three to five minutes later. They are visible only at wavelengths ranging from 700 nm to about 900 nm.
SCP-966 feed on medium-to-large sized animals, including humans. They hunt either alone or in pairs. Their hunting methods consist on emitting a single burst of a previously unknown type of wave, which permanently inhibits the ability of the affected creature to enter in any of the NREM and REM sleep stages. The ability to micro sleep is also lost.
Other than the common symptoms caused by sleep deprivation, some victims of SCP-966 have shown signs of suffering from extremely vivid hallucinations, as well as sudden bouts of rage with no apparent external stimuli. It is currently thought that these are the effects of prolonged exposure to the waves. Why SCP-966 continually exposes these waves to only some of their victims is unknown. One hypothesis is that SCP-966 will only do this when starving, since it further degenerates the physical and mental state of their prey, incapacitating it at a faster rate.
After depriving their victims of sleep, SCP-966 will stalk their prey until the lack of rest incapacitates it. At this point, SCP-966 will proceed to consume it. SCP-966 have proved to be very agile and silent while stalking their victims. On occasion, they will deliberately make threatening noises around the prey in order to further stress it, and may even physically assault it if the victim proves to be particularly durable.
SCP-966 instances can be found in their containment chamber and in the maintenance tunnels. They are only visible when the player is wearing a pair of night vision goggles, although their sounds can still be heard when nearby regardless and the player is still able to collide with the instances. If the player approaches an instance without wearing the goggles, a message will be displayed, reading "You feel something breathing right next to you".
The instances will walk around the facility. Should the player approach an instance, it will look up at them and begin emitting a sound that will decrease stamina regeneration significantly. This is signified by the player's vision becoming blurred for a few seconds. Should the player remain close to an instance for a period of time after the sound is emitted, they will pursue and attack the player. The instances, however, are slow and easy to evade; unfortunately, they may prove difficult to avoid should the player not have night vision goggles.
In-front of player:
Sometimes your character will note "You can feel something near you, but you are unable to see it, perhaps its time is now." which is a reference to the meme centred around John Cena's theme music aka "You can't see me, MY TIME IS NOW"