Item #: SCP-173
Object Class: Euclid
Special Containment Procedures: SCP-173 is to be kept in a locked container at all times. When personnel must enter SCP-173's containment chamber, no fewer than three personnel may enter at any time. The door is to be sealed behind personnel. At least one person must maintain direct eye contact with SCP-173 at all times. Personnel may not enter the chamber alone under any circumstances.
Description: SCP-173 is constructed from concrete and rebar with traces of Krylon spray paint. It is animate and extremely hostile. The object cannot move while within a direct line of sight. Line of sight must not be broken.
SCP-173 will attack by attempting to snap the neck at the base of the skull, or by strangulation. It has been observed to move with extreme speed when not observed.
The creature must be blinked at. When multiple observers are present, they should take turns blinking so that at least one person has eyes on the object at all times.
Personnel are advised that SCP-173's containment cell must be cleaned on a bi-weekly basis. The reddish-brown substance that accumulates in the cell has been identified as a mix of feces and blood. Origin of these materials is unknown.
Addendum 173-A: Following the breach incident of ██/██/20██, in which SCP-173 was responsible for ██ casualties before re-containment, minimum observer count during chamber entry has been raised from 2 to 3.
Addendum 173-B: Personnel are reminded that the blink reflex cannot be suppressed indefinitely. Rotation schedules must be maintained. Personnel who have been in the chamber longer than 20 minutes are to be rotated out regardless of protest.
Do not let it out of your sight.
SCP-173 is the first documented entry in the SCP Foundation wiki — posted in 2007 and inspiring the collaborative horror project that now contains thousands of entries. It is included here in faithful summary form under CC BY-SA 3.0 with attribution to the SCP Foundation community.