Styles and Variations
The opening title sequence shows images that are not shown within the actual series itself, with exception of the Mulder and Scully stop-motion sequence entering a room, which was taken from the "Squeeze" episode, as the sequences were filmed for the title sequence only. It shows images from a flying saucer in midair, pod-like objects opening, an invisible being walking down a hallway, and stretched face. The title sequence also introduces two main cast members David Duchovny and Gillian Anderson and also series creator, Chris Carter, is credited in the sequence as "Creator".
From seasons 1 through season 7, the opening title sequence remained the same; showing the same images and the same theme song. Starting from season 3, the opening title sequence reduced its run time, displaying fewer images, to allow more time for the episode itself as the full title sequence is near a minute long.
Season 8 had a new Opening Title Sequence to introduce Robert Patrick who would remain for the rest of the original run. In episodes that Duchovny did not appear in, his name was completely removed from the sequence. The only cast and crew names within the sequence are: Gillian Anderson, Robert Patrick, and creator Chris Carter. The season 8 title sequence also showed new images to match the situation of the characters and events within the new season. New images like Fox Mulder falling into dark hole which resembles the iris of an eye, a short of Dana Scully and John Doggett investigating in the field at night, and also Scully's child, William, as a growing fetus.
The opening title sequence changed once again in season 9 with a new edited theme song and new images as Duchovny had fully departed while Annabeth Gish and Mitch Pileggi now being promoted to series regulars. The title sequence now had five cast and crew names within the sequence as it still showed Carter's name.
In the series finale, "The Truth", Duchovny returned and this time his name was placed into the opening title sequence making the final episode's opening title sequence the sequence with the most cast members mentioned as it displayed: Gillian Anderson, Robert Patrick, Annabeth Gish, Mitch Pileggi, and David Duchovny.
Today, The X-Files opening title sequence is considered to be one of the greatest in television history. Paul Rabwin claimed that the title sequence is something "Never seen on television before." It is unforgettable for fans and viewers due to it being dark and mysterious