SCP-966, or "Sleep Killer", is an upcoming SCP in SCP: Unity that will be added in an as of yet unannounced update.
SCP-966 are predatory creatures that resemble hairless, digitigrade humans, possessing an elongated face with a mouth lined with needle-like teeth. On each hand, they have five claws that can be up to 20 cm long. Although sharp, these are easily broken, making them unfit for combat. SCP-966's height ranges from 1.4 to 1.6 meters, and they can reach up to 30 kg in weight. Physically, SCP-966 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.
SCP-966 are visible only at wavelengths ranging from 700 nm to about 900 nm. This applies to all of SCP-966's tissues. If their skin, muscles or organs have suffered from second to third-degree burns, the affected areas will be visible at wavelengths ranging from 360 to 900 nm.
SCP-966 feed on medium-to-large-sized animals, including humans. They hunt either alone or in pairs. Their hunting methods consist of emitting a single burst of a previously unknown type of wave, which permanently inhibits the ability of the affected creature to enter any of the NREM and REM sleep stages. The ability to micro-sleep is also lost. The effective range of the ██████ waves is up to 20 meters; however, tests show that they can be blocked by post-transition metals, particularly lead.
All attempts to make victims of SCP-966 sleep have failed. It is still possible to induce other forms of unconsciousness, although these will usually prove detrimental to the affected subject as they do not provide true rest.
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 is not currently in-game