SCP-901-TH which had already been cleaned before it was brought into containment for the first time.
Item #: SCP-901-TH
Object Class: Euclid Safe
Special Containment Procedures: SCP-901-TH is contained in a glass cabinet in Zone A2 A1. The object is currently classified Euclid Safe and stored at Warehouse-29a (transferred on 29/03/20██). SCP-901-TH will be checked for decay and cleaned every 3 months by Level 3 personnel. As is the standard for other objects in Zone A1, further testing the object has been discontinued. All prior testing logs can be found attached in the Addendum.
Description: SCP-901-TH is a handcrafted paperboard-and-brass mask designed to resemble the head of a Giant. Non-anomalous variants of the mask are often used for theatrical performances. SCP-901-TH adapts to a subject's cranium even when the object appears to be smaller than his or her head. SCP-901-TH is recorded to have been used only once in performance due to the effect it has on the wearer. The incident was recorded at a practice session of ██████████ at 12/08/19██; see Incident 901-A.
SCP-901-TH's effect on the wearer is akin to 'possession by a spirit'. The wearer will be possessed by an unknown entity that appears to entirely suppress the host's 'spirit' while further amplifying the host body's strength. Subjects are noted to act rabid and will injure or attempt to kill any life in the surrounding vicinity. All attempts to remove SCP-901-TH from the subject's head while the subject is still alive have failed. The best method, according to testing, is to remove SCP-901-TH postmortem.
Test subjects that wear SCP-901-TH for long periods of time will begin growth of extra appendages at a rate comparable to Anolis Carolinensis, though accelerated. These appendages are usually arms and hands which grow on the side or back of the host's body in 4-5 pairs and typically are connected to the backbone or rib-cage. How the growth of this additional limbs occurs is yet unknown as testing has been canceled. Removing SCP-901-TH from a subject after the appendage's growth will not remove the new limbs.
Addendum: On ██/██19██, D-632 was tested with SCP-901-TH in a concrete testing chamber. After wearing 901-TH for a while, D-632 began to rapidly move about the room, attempting to take SCP-901-TH off by himself before running head-on into a wall until cracks formed. Despite obvious damage, D-632 was able to stand regardless of major head trauma. Afterward, his back grew a set of appendages in the shape of arms. Four agents were ordered into the room to terminate D-632, of which the subject killed two and severely injured a third by mutilating the legs. Attempts to stop the subject via firearms failed. The subject proceeded to run out of the testing area and killed all personnel within sight, tearing their bodies apart by hand. The subject's rampage was ended via decapitation by Agent Philosafix.