Black Goo

The Black Goo is a conspiracy theory revolving aroud a supposed demonic entity that is blamed for many paranormal events - almost always of a malevolent nature, the entity itself is said to be a tar-like mass of black goo with sapience, its origins are considered to either be Satanic, extra-terrestrial or a form of artificial intelligence depending on the conspiracy theory at play.

The Black Goo is popularized in 90s culture via the Purity virus from the X-Files.

General Info
The Black Goo is a mysterious and evil entity that causes victims to become sick, drives them mad or corrupts them into performing all manner of criminal activities - often it is said to emit the smell of sulphur and moves of its own accord - the entity is said to actively take interest in the corruption of those around itself and is linked to either a demonic conspiracy to take over the world or aliens, who also wish to conquer the world : some theories also speculate it as a rogue artificial intelligence akin to the Grey Goo, or a secret weapon utilized by the Illuminati.