On The X-Files television show, the term Men in Black refers to a group of enforcers employed by the Syndicate to execute assassinations, cover-ups and other clandestine operations.
As of the series finale, it is assumed they have been phased out, as the "New Syndicate" (Super Soldiers) does not have as great a need to employ normal humans.
X was a high-ranking member of the Men In Black (MIB), a group of operatives used by The Syndicate to carry out their dirty work.
Trapped on a train car equipped with a time bomb, Mulder, about to escape, is attacked brutally by an MIB assassin.
When suspicion arises after the finding of photographs that were taken of The Smoking Man by X, false information is planted at the First Elder's behest, in order to root out the leak.
Attempting to relay the information to Mulder, X goes to his apartment and is surprised by fellow MIB operative, the Gray Haired Man, who fatally shoots him.
In the season one finale, "The Erlenmeyer Flask", Crew Cut Man is working with a couple of other Men in Black to terminate all evidence of a covert alien-human hybrid program, which Mulder was investigating.
[8] Scully witnesses the murder and later, in the season two episode "Red Museum", she recognizes him during a case in remote Wisconsin, where secret experiments with alien DNA were being conducted.
While Mulder was being held, his cell phone was left unanswered by Crew Cut Man, as he remarked that he had "this thing about unsecured lines.
The Grey-Haired Man, played by Morris Panych, was first shown, along with other fellow MIB operatives, attempting to deter Skinner from reopening Melissa Scully's murder investigation.
[14] Man in Black #1, played by Jesse Ventura in the comedic episode, "Jose Chung's From Outer Space".
[16] Dark Man/Moustache Man/Scott Garrett, played by Greg Michaels, was a Man in Black employed to aid a Syndicate cover-up.
[18] Scott Ostelhoff, played by Steve Makaj, was an MIB operative with Department of Defense credentials, working for the First Elder.
He was tasked with murdering the members of an expedition team that was attempting to excavate a recently discovered alien corpse, which was actually an elaborate hoax.
[20] At a later date, he was appointed by the Well-Manicured Man to investigate the mysterious deaths by burning of Syndicate scientists involved in the human-alien hybrid program.
[24] He is later ordered to spy on Scully in the season 7 episode "En Ami", and almost kills her via sniper rifle, but is dispatched by his superior, The Smoking Man.
[26] In 1998, as a result of an incident with UFO technology accidentally caused by General Edward Wegman, Fletcher switched minds with FBI Special Agent Fox Mulder.
He then finds himself aiding the Gunmen in tracking down their enigmatic acquaintance Yves Adele Harlow in the belief that she worked for Romeo 61, a government-sponsored wetworks unit.
Using FBI Special Agents John Doggett and Monica Reyes, Fletcher tracked down Harlow and helped prevent a massive genetically engineered virus from being released in New York City.
[29] Howard Grodin and Jeff Smoodge, played by Michael Buchman Silver and Scott Allan Campbell respectively, were co-workers of Morris Fletcher at Area 51.