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Villains from The X-Files TV show and films, as well as associated media - the series is famous for popularizing the idea of alien conspiracy and anti-government resistance as well as a colorful array of monsters that helped to create the "Monster of the Week" style horror and sci-fi that has become a staple of supernatural entertainment.

This can also include antagonists featured in the Lone Gunmen and Millennium, two series also set in the same universe as X-Files.