For 11 seasons, The X-Files led viewers on a wild chase to uncover a truth that was always out there, no matter how deep it was buried. An influential one in the genre, the sci-fi series combines elements of crime procedurals and paranormal mysteries like never before by dragging a spooky Mulder and skeptical Scully into battles with murderers, aliens, murderous aliens, and forces beyond human understanding.

Most of the episodes in the series followed a "monster-of-the-week" approach, but The X-Files also had an overarching mystery about government conspiracies and mitigated arcs that went on for seasons. Debuting in 1993, it arrived at the height of people’s intrigue surrounding aliens and the Area 51 fever, which only hooked the audiences more to its brilliant premise.

While it maintained the atmospheric chills and cleared the way for more supernatural/sci-fi TV shows, the series also features a dozen guest stars, actors who had yet to make it big in the industry. Early in their careers, stars like Ryan Reynolds, Shia LaBeouf, and Bruce Campbell showcased talent and promise beyond their years. Looking back, it seems as if The X-Files was foretelling their future success in movies and television.

10 Tony Shalhoub

Long before his multiple Primetime Emmy wins for Monk, Tony Shalhoub cut his teeth in a silly but terrifying X-Files episode. In season two, episode 23 titled "Soft Light," Shalhoub plays the role of Dr. Chester Ray Banton. Banton is a physicist who is so obsessed with the idea of dark matter that through rigorous experimentation, he turns his own shadow into a void that burns anyone who walks into it. After watching Patrick Newirth, a hotel guest evaporate in front of his eyes, Banton flees. But Dana and Fox are hot on his heels.

Tony Shalhoub Shows His Talent Early On in The X-Files

Shalhoub went on to demonstrate his remarkable gift for acting in roles that walked a thin line between good and evil. He first became the obsessive-compulsive detective Adrian Monk, blessing us with one of the most deeply understandable characters in the genre. He also lent humor to supporting parts in movies and was awarded an Emmy for Best Supporting Actor in a Comedy Series for his role as Abe Wiessman in The Marvelous Mrs. Maisel.

9 Seth Green

He is now popular for voicing Chris Griffith in Family Guy, but Seth Green made his debut in television and movies by taking up small roles. In "Deep Throat," the second episode of the first season, Seth Green played the role of Emil. He is a teenager trespassing into a military base with his girlfriend Zoe, when the two catch a glimpse of a UFO flying overhead. Later, he is seen narrating his experience to Dana and Fox while being treated to a meal.

Seth Green Showcasing His Wit

The role was brief but crucial to the episode. Post X-Files, Green would bounce between cult hits like Buffy the Vampire Slayer and movies like Can't Hardly Wait and Austin Powers: International Man of Mystery. Clearly, Green has a natural skill for showcasing his wit and letting his comedic timing and range shine in the unlikeliest roles. Nearly four decades in the industry and Seth Green is still a genre mainstay.

8 Jane Lynch

A legendary scene-stealer in comedies, Jane Lynch had an excellent appearance in a "monster-of-the-week" episode of The X-Files. In season nine, episode five, "Lord of the Flies," Lynch plays the role of Anne Lokensgard, an authoritative and formidable school principal to Aaron Paul’s David. The episode was also Paul’s guest-star appearance before he became known for Breaking Bad. It is later revealed that Anne is actually some sort of human-insect hybrid.

Jane Lynch Shows Off Her Horror Skills

Lynch's cunning and calculated side was a testament to how impactful her work was on the audience. It was the first time she showcased her skills for blending comedy and horror in the most sublime ways. Since then, she has shone, among others, as Sue Sylvester in Glee, Paul Rudd's boss in The 40-Year-Old Virgin, and Sophie Lennon in Prime Video's The Marvelous Mrs. Maisel. Whether nurturing or naughty, Lynch always generated laughter and her performances remain poignant and memorable.

7 Octavia Spencer

Octavia Spencer won an Academy Award for her role in The Help, and the actress’ ability to portray feminine strength and steely resolve has been apparent in movies like Hidden Figures, Gifted, and The Shape of Water. While having built an incredible career around her gifts, it took Spencer a while to come into the limelight.

Octavia Spencer in an Early Boundary-Pushing Role

In an early standout role, Octavia played the role of a nurse at a mental hospital in season 7, episode 4, titled "Millenium," which was a crossover episode. As Spencer continues to choose roles that push boundaries, highlight tough and intelligent women, and start hard conversations, rest assured we will be graced with more remarkable turns.

6 Titus Welliver