Eugene Tooms first appears in the episode “Squeeze.”
“Squeeze” is the third episode of The X-Files’ first season and originally aired on September 24, 1993. Doug Hutchison plays Tooms, a mutant serial killer who can stretch and compress his body enough to pass through narrow openings. He targets victims roughly every 30 years, killing five people before entering a period of hibernation.
Mulder recognizes a connection between Tooms and a series of murders dating back to 1903. Although Tooms passes most of a polygraph examination and is released by skeptical investigators, Mulder and Scully eventually uncover evidence linking him to earlier crimes. The episode’s most memorable sequence shows Tooms squeezing down a chimney to reach a victim.
Tooms returns in the first-season follow-up “Tooms,” which concludes his original storyline. “Squeeze” is also important to the series’ development because it helped establish horror as one of The X-Files’ defining genres. The character is sometimes associated with “Tooms” because of that second appearance, but his debut is firmly in “Squeeze.”