Per 
Gaseous Human Shadow
Item #: SCP-XXXX
Object Class: Euclid
Special Containment Procedure: SCP-XXXX will willingly go where it is told, as long as the light is either dim or nonexistent, and is therefore in an air tight cell that is perpetually dimly lit. SCP-XXXX will mirror emotions and actions of those nearby, so those who do interact with SCP-XXXX must remain calm at all times, however interaction with SCP-XXXX is extremely advised against. SCP-XXXX is under constant surveillance from a single camera in the corner of its' cell.
Description: SCP-XXXX is humanoid in shape, yet has the properties of a gas. SCP-XXXX is primarily dark, almost black around it's entire body except for what is assumed to by eyes and a mouth, which are a ruby red. The hands and toes are lanky and come to a fine point, and the gaseous properties of SCP-XXXX make it appear that wisps of a dark gas emanate from it's entire body, however scientists have not been able to capture any of the gas for experimentation, nor have they located the source of this perpetual gas. SCP-XXXX's size and shape varies with whomever is present within the room with it, but observation shows that its' resting form is about 1.8 meters tall. If there are multiple humans in the room, it will copy the form of whichever human it makes eye contact with. SCP-XXXX does not appear to have the need nor desire to consume anything and will remain immobile for long periods of time when no human interacts with it, however guards observing the cameras in SCP-XXXX's cell swear that it moves when they are not looking at it.
Upon interviewing SCP-XXXX, it has been observed that it does not speak, but can respond with visible nods or shakes of the head. SCP-XXXX has shown instances of understanding arithmetic and science, yet occasionally will not repeat these results depending of the interviewer. Our scientists theorize that SCP-XXXX may not only mirror physical qualities, but also the knowledge of those it mirrors, making it extremely dangerous. No one who has a B-Class or above status is permitted to interview SCP-XXXX since it is not known whether or not it stores the information it has gathered.
Researchers have presented SCP-XXXX with a variety of animals to see how it reacts, however SCP-XXXX appears to not notice the animals. The animals do not appear to take note of SCP-XXXX either, however when they come close to SCP-XXXX and inhale its gas, they immediately recoils and attempts to run to the farthest corner of the cell. The only reaction that comes from SCP-XXXX is when a groundhog is presented, and it attempts to hide from the specimen until the groundhog is removed, upon which SCP-XXXX becomes immobile once again.
Discovery Log: Initial contact with SCP-XXXX led to the permanent blindness two Foundation members, █████ and ███ . Reports of a demon that watched people while they sleep circulated around a small town in southern Kansas, and stories of this "demon" made way to the Foundation. The Foundation ran a fake-sleep operation to lure SCP-XXXX out. When SCP-XXXX came to the operation, multiple Foundation members came out from hiding spaces to approach and interact with it. However, a mistake was made when two Foundation members shone their flashlights directly into the red eyes of SCP-XXXX, causing it to increase the production of its' gas and silently scream, yet the two Foundation members recount a blood curdling scream. At this instant, the Foundation members fell to the ground, clutching their eyes, shouting that they could not see. After this, the production of gas subsided and it once again became calm. No member of the Foundation lifted their flashlights, and calmly asked SCP-XXXX to come with them. SCP-XXXX obliged and followed one Foundation member to an air-tight containment vessel, where it was transported to Site 43.
Additional Notes: SCP-XXXX has appeared to be observed before capture in southern Kansas in London during the early 1900's. Reports have shown that a young teenage boy dressed in green to be flying around the city of London with a dark figure in similar proportions close in tow. It is unclear whether the green flying teenager is also an SCP or a byproduct of prolonged exposure to SCP-XXXX.
