Per 
Special Containment Procedures: The entrance to SCP-XXXX entrances are not to be covered under any circumstance and 2 armed guards are to be stationed outside the entrance at all times. Any personnel entering SCP-XXXX are to be apprehended and punished accordingly. Any personnel authorized to study SCP-XXXX are not to be within SCP-XXXX for longer than 10 minutes. A detachment of Zeta-9 is to be on standby in case of the need of a search and recovery team. Any civilians to enter SCP-XXXX are to be recovered and administered Class B amnestics before being released.
A routine investigation of disappearances in the area should occur every year along with an aerial search around the tunnels for entrances. Any new entrances that are found shall be immediately searched for civilians and the previous procedures should be put in place.
Description: SCP-XXXX are a system of tunnels in the Son La province of Vietnam that were constructed in 1969 and were in use until 1975. Although the exact size is unknown, the tunnel system is approximately 35 kilometers in length and expanding, with a further 10 to 14 kilometers being dug by SCP-XXXX-1 every year. This typically includes 1 to 2 new entrances into the tunnels. The exact depth of the tunnel system is unknown. The tunnel itself is 80 centimeters wide and 80 centimeters in height, although has been noted to be smaller on rare occasions. Any attempts to cover or fill the entrance of the tunnel system leads to a further two entrances being created in the week following by SCP-XXXX-1.
SCP-XXXX has the anomalous factor of constantly shifting pathways and walls, tunnels have been observed shifting after breaking visual contact with them. The tunnels shift seemingly at random and all attempts to map the system have failed. It has also been observed that after 10 minutes in SCP-XXXX subjects start to feel disoriented. This includes headaches, confusion, loss of direction and eventually unconsciousness.
The presence of traps within SCP-XXXX makes returning from expeditions inside it extremely difficult in combination with the anomalous ability. These non-anomalous traps are placed seemingly at random throughout the tunnels beyond a 100 meter radius of entrances. These traps include spike pits tipped with urine and feces, tripwires that lead to venomous snakes, bees, and other creatures, cave-ins of the tunnel, flooding, hot tar, explosives, and the release of toxic gas.
SCP-XXXX-1 is a humanoid, quadruped entity that resides in and builds SCP-XXXX. SCP-XXXX-1 is a Vietnamese male but is extremely mutated. These mutations include a loss of pigmentation in the skin and eyes to possibly acclimate to the constant darkness, long, sharp finger nails, a longer than average torso, and short legs leading it to be 1.1 meters in height. This body composition allows the entity to effectively crawl around the tunnels. SCP-XXXX-1 wears a ripped Viet Cong military uniform. The entity is able to crawl and move throughout the tunnels at high speeds and seems to be able to understand the sporadic changing of the tunnels. This can be observed when a subject makes visual contact with SCP-XXXX-1 in which it will attempt to crawl away; the tunnels sporadically change behind SCP-XXXX-1 during this time. SCP-XXXX-1 also has the ability to give migraines to anyone within a 20 meter radius, or any subject that attempts to harm it.
Addendum: SCP-XXXX was first found in 1988 after the investigation of multiple disappearances in the Son La district of Vietnam. When the entrance of the tunnel was first found, a search party of local law enforcement and Foundation agents were sent into the tunnel. After contact was lost with the party Mobile Task Force Zeta-9 (“Mole Rats”) were organized to investigate the tunnel system. After 11 casualties were reported, Zeta-9 retreated and the area around the entrance was put into Foundation custody.
