Trivia: Scully's father, Scully's older brother, and the man Mulder thought was his biological father were both named William. (The father who raised Mulder went by "Bill, " as did Scully's brother.) Mulder's actual biological father, Cancer Man, was played by William B Davis (who also goes by "Bill"). Scully and Mulder's son was also named William (before being adopted and having his name changed to Jackson).
Brutal Youth - S4-E5
Trivia: Jack Larson, who played Jimmy Olsen in "The Adventures of Superman" in the 50s, portrays Jimmy Olsen as an old man.
A Long Walk To Pittsburgh (2) - S4-E17
Trivia: Topanga is talking to Cory and she says, "My Aunt Prudence wouldn't even know who Romeo and Juliet are!" When her Aunt Prudence knocks on the door, she is played by actress Olivia Hussey, who played Juliet, in the 1968 film Romeo and Juliet, also starring Leonard Whiting as Romeo.
If Wishes were Horses - S1-E16
Trivia: Buck Bokai, a baseball player from the 21st Century, who becomes "real" in this episode, broke Joe DiMaggio's consecutive hitting streak in 2026. While he's not physically seen or referred to by name, this fact is mentioned in the 'Star Trek: The Next Generation' episode "The Big Goodbye."
Trivia: John Munch is the only fictional character played by a single actor to appear on eight different TV series. He was a series regular on Homicide, and crossed over onto "Law & Order", "The X-Files", "The Beat", "Law & Order: Trial By Jury", "Arrested Development", "The Wire", and became a series regular on "Law & Order: Special Victims Unit".