Sleep Killer

 It is a predatory creature that resembles hairless, digitigrade human, possessing an elongated face with
a mouth lined with needle-like teeth. On each hand, they have five claws. 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
an unknown type of wave, which permanently inhibits the ability of the affected creature to enter any sleep stages.
The effective range of the waves is up to 6 meters; however, tests show that they can be blocked by
post-transition metals.
After depriving their victims of sleep, SCP-966 will stalk their prey until the lack of rest incapacitates it.
SCP-966 have proved to be very agile and silent while stalking their victims.
They will attack the victim when it has reached final stage of sleep deprivation.
They can be seen via Night vision goggles.