Species: scp-1499-1
SCP-1499-1 are a species of monstrous humanoids from the mythos of the SCP Foundation website. Their debut story, SCP-1499 — The Gas Mask, was posted in 2012 by a writer known as Trasknari.
SCP-1499-1 are tall humanoid monsters experienced by wearers of SCP-1499. Instances are described as nude dark-skinned bipeds with an excessive amount of eyes and mouths across their bodies, along with a thick coat of an unknown viscous substance and various minute differences in their mutations.
SCP-1499-1 behavior is poorly documented, but they have been observed committing violence against one another and occasionally vocalizing with low, grating sounds. In one exploration, numerous SCP-1499-1 were observed congregating in a location to sing from all their mouths and perform what appeared to be a ritual where a leader cut open its chest and used its heart to summon a large worm-like creature from a portal.
The reliability of their observation is highly questionable, as SCP-1499-1 are almost certainly hallucinatory in nature; in reality, SCP-1499-1 are ordinary humans perceived as monstrous through SCP-1499's lenses. During the aforementioned exploration, Agent K█████ believed he was fighting through SCP-1499-1 to stop a cult's eldritch ritual, when he was in fact unknowingly committing a mass shooting at the Cathedral of Christ the Saviour in Moscow, Russia, brutally killing six "SCP-1499-1" and ripping the priest's heart out.