SCP-173 is animate and extremely hostile. The object cannot move while within a direct line of sight. The line of sight must not be broken at any time with SCP-173. Personnel assigned to enter the container are instructed to alert one another before blinking. The object is reported to attack by snapping the neck at the base of the skull, or by strangulation. In the event of an attack, personnel is to observe Class 4 hazardous object containment procedures. The object can't speak.