SCP - 173 from the SCP foundation. Secure, Contain, Protect. SCP - 173 is a EUCLID class object. It is animate and extremely hostile. The object cannot move while within a direct line of sight. Line of sight must not be broken at any time with SCP-173. Personnel assigned to enter container are instructed to alert one another before blinking. Object is reported to attack by snapping the neck at the base of the skull, or by strangulation.