Per 
Photo of SCP-XXXX-1 while fences were being installed.
Item #: SCP-XXXX
Object Class: Euclid
Special Containment Procedures: SCP-XXXX-1 is to be constantly surrounded by a barbed wire fence. Guard posts are to be placed on all four corners of the fence. If any activity unfamiliar to SCP-XXXX occurs, members of MTF Zeta-9 ("Mole Rats") are to be dispatched to the area from Outpost 861.
SCP-XXXX-2 is to be momentarily checked on via remotely controlled cameras. SCP-XXXX-2 does not require any containment measures as it does not pose any immediate threat.. (see Addendum XXXX.1) Metal chains are to be wrapped around the handles of SCP-XXXX-2. Engineering staff accompanied by Zeta 9 members should inspect the chain weekly. If the chain at any point breaks on SCP-XXXX-2 from an anomalous source, Zeta 9 are to respond IMMEDIATELY.
SCP-XXXX-3 is contained by the containment measures of SCP-XXXX-2. Any attempts of researchers to put any audio/visual devices into SCP-XXXX-3 is to be denied.
Description: SCP-XXXX-1 is a hole in the ground within the ████████ Deserts, off I-██. It is approximately 8 yards wide in diameter on the surface, between the two farthest points. SCP-XXXX-1 leads to a cave system. In total, there are 4 caverns, separated by rock walls and crevices. Excavation projects have been held to make easy passage through the caverns.
In SCP-XXXX-1, there is, what appears to be, a main cavern. It is roughly 42 yards deep at its farthest point. Within this main cavern, is a set of double doors. Several inscriptions are present, but have eroded to the point beyond recognition. The area behind the door will be referred to as SCP-XXXX-2.
SCP-XXXX-2's door appears to be constructed out of stone. It appears that some sort of red paint was applied, but has almost completely flaked off. The door itself doesn't appear to be anomalous. (see Addendum-XXXX.1) Activities of the door include vigorous rattling, slamming shut and opening anomalously.
The room behind SCP-XXXX-2 will be referred to as SCP-XXXX-3. SCP-XXXX-3 is a medium, carved chamber behind SCP-XXXX-2. It appears to be of primitive origin, as cave paintings and unrecognizable rock sculptures are present in the room. A large, ritualistic symbol is painted on the floor.
Addendum:
Addendum-XXXX.1: The following is a video log on (MM/DD/YY) 9/18/201█.
Foreward: This video log was captured from the remotely controlled camera monitoring SCP-XXXX-2.
[BEGIN LOG]
13:32: SCP-XXXX-2's door can be seen rattling.
Zeta 9 had been informed of the disturbance and had begun to descend within the cave.
13:43: Zeta 9 entered the cave system. The door's rattling intensity had significantly increased. The previously documented droning sound can be heard through the camera's microphone.
13:56: The camera's visual began to distort. The visual significantly dropped in quality and, every now and again, the camera would completely distort, making any visual completely useless.
14:03: Four Zeta 9 members that have spelunking gear on come into frame and look at the rattling door. The squad commander exits frame, talking on his radio. The other Zeta 9 members approached the rattling door, one remained at a safe distance. The following audio can be heard.
Unit remaining at distance: What are you doing? Get away from it!
Unit approaching #1: Don't be a chicken, it's just a rattling door. You can't be a Zeta 9 member if your scared of a door.
Unit remaining at distance: Do you even remember what our job is? Did you hear about that mother-(unintelligible) shy guy thing? What if one creepy thing jumps out of that door?
Unit approaching door #2: What's the chance that one is going to jump out? Hu-
14:05: The camera audio fully distorts, a screen of static. The droning from within SCP-XXXX-2 intensifies. The door to SCP-XXXX-2 can audibly be heard being slammed open. A few screams are heard as a thud is made. Gun fire plays through the audio. Heavy footsteps trail off into the distance. "NOO-!" can be heard, before a crunch ends the sentence. What sounds like a horse galloping can be heard trailing off. Several organic clicks, most likely resulting from the creature, dissipate as the footsteps get quieter.
14:08: The screen of static ends. 2 corpses are seen on the floor. Both of the corpses are the units who approached SCP-XXXX-2's door. The unit who stayed back from the door is not visible. Unit #1 has his [REDACTED] tore out. #2 can visibly be seen [REDACTED].
14:11: The camera heavily distorts as the clicking returns and the horse galloping comes back and then trails off once more. SCP-XXXX-2's door is heard shutting.
14:12: The camera stops distorting and nothing in the scene is changed from time stamp 14:08 except SCP-XXXX-2's door is closed.
[END LOG]
Closing Statement: SCP-XXXX-2 is to be constantly locked to prevent any incident similar to this from happening again. Both units that were seen dead in the video were deemed KIA. Private Gare, the one who remained at a safe distance, was the only survivor with eyewitness, as he stated that the "monster" had attacked his colleagues first, rather than him.
