X-Files, The
TV Series: Season 01; Episode #16: "Young at Heart"
Mulder investigates a crime that appears to have been committed by a criminal he helped put away, who was supposed to have died while being operated on by a doctor who was experimenting on reverse aging, and regrowing limbs using salamander cells.
The X-Files
TV Series: Season 02; Episode #19; "Dod Kalm"
Mulder and Scully investigate a rusty derelict ship that speeds up their aging process, and they must find a cure before they die of old age. The makeup effects are simply awful...Mulder ends up looking like a Star Wars prune alien and Scully looks like a rotting, welted corpse. No makeup is even applied to their hands, and their hair is still normal, even at a supposed 90 years. Great idea and story, but horrible makeup ruins it.
--Zietgiest
X-Files, The
TV Series: Season 05; Episode #06: "Christmas Carol"
(flashback dream sequence) Young Scully sees herself as an adult. Scully also learns she's a mother.
-- Visible Time
X-Files, The
TV Series: Season 05; Episode #17: "All Souls"
Retreating beneath the staircase Scully finds a girl, whom she tries to lead to safety, but once again her good intentions are foiled when the girl morphs into her daughter Emily and asks to be let go.
X-Files, The
TV Series: Season 0?; Episode #??: "All about Eve"
Scientist makes clones of herself.
-- Visible Time