Black Oil Worms - Black biotoxin of extraterrestrial origin that congeals into tiny worms and penetrates human orifices on episodes of the fantasy drama THE X-FILES/FOX/1993-2002. The Black oil (aka "Purity") appeared in the episodes  "Piper Maru," "Tunguska,"  "Terma," "Patient X" and "The Red and the Black." On episode "Tunguska" Special FBI agent Fox Mulder (David Duchovny) is strapped to a table, held firmly in place by a blanket of chicken wire, infected with the oily black worms and then injected (in his left arm) with an amber liquid. The inhuman experiments were an attempt to create a vaccine against the alien virus. The black oil's filmy membrane could be seen swimming across the surface of it host's eyes. Once infected, the host's will was under the control of the black oil organism and after an incubation period an alien being would feed on its host then burst from its body. Traces of the black oil were discovered inside a four-billion-year-old rock found in Tunguska, Siberia, the site of a cataclysmic fireball from space that hit the region in 1908. The black oil also appeared in the feature film spin-off The X-Files: The Movie (1998). A variation of Black Oil called "Black Cancer" will cause a paralytic stupor when injected into human test subjects. The Black Cancer is the lifeless remains of Black Oil. The Black Cancer cellular structure is identical to the Black Oil and was used to develop a virus to neutralize the living Black Oil.