Per 
Item #: SCP-3873
Object Class: Euclid Keter
Special Containment Procedures: SCP-3873 should be constantly monitored for any movement, and heat signatures. Any airborne vehicles must be redirected as to not reveal position of SCP-3873. Oerlikon GDF AA weapons must be online and manned at all times. Any entities exiting SCP-3873 must be destroyed immediately.
Description: SCP-3873 is an invisible mass made of the same elements as there are in the ozone layer. However, SCP-3873 resides only 609.6m in the air, over the now abandoned town of ████████, Utah. SCP-3873 contains translucent entities only visible when outside of SCP-3873. These entities are classified SCP-3873-1.
SCP-3873 is capable of flight, though not being aerodynamic in the slightest. SCP-3873-1 are hostile and will attack any animals, including humans. SCP-3873-1's hunting patterns consist of causing deep dread in its prey. Once prey is on high vigilance, SCP-3873-1 will "play" with its prey, often making objects fall over, startling the prey. ("Prey" will now be known as SCP-3873-2) After about 5 minutes of this, SCP-3873 will lift SCP-3873-2 into the air, carrying them into SCP-3873. SCP-3873-2 is at this point considered lost, and no rescue will be attempted.
SCP-3873 is capable of movement at random intervals, usually only moving rapidly back and forth, much like vibrating, however SCP-3873 has been recorded moving as many as 3500km in three separate incidents. SCP-3873-1 isn't completely bound to SCP-3873, and is free to move as far is it needs to to find someone suitable for SCP-3873-2, although they will always return to SCP-3873.
Addendum 3873-1: Discovery
SCP-3873 was discovered with disappearances in █████████, Nevada of both humans and livestock. Law enforcement, then FBI agents were sent only to disappear, bringing foundation interest. █ casualties were suffered as there was an assault from both sides. Explosives seem to be the only things that affect SCP-3873-1.
Addendum 3873-2: Change
SCP-3873 was observed spontaneously combusting on ██/██/2011. Staff assumed it was neutralized. 2 months later, SCP-3873 was found in ██████, Colorado. The same thing was observed a second time, having SCP-3873 transport to ████████, Arizona, and a third time, to ████████, Utah.
