“The Host”, the second episode of The X-Files’ second season, introduced the Flukeman, a humanoid sewer creature with a giant flukeworm mouth. The episode follows Mulder investigating a waterlogged body in New Jersey’s sewer system while the FBI’s X-Files division is shut down, eventually uncovering attacks at a sewage treatment plant. Its standalone story, memorable design and strong practical effects helped establish it as one of the show’s most celebrated “Monster of the Week” episodes.

The Flukeman was notable for its bright white appearance, unusual anatomy and cinema-quality creature effects, which were relatively uncommon on television at the time. The story also linked the creature to the Chernobyl disaster, adding a contemporary science-fiction element, while its independence from the wider alien conspiracy made it easy to revisit. Despite appearing in only one episode, the character became an unofficial mascot for the series’ standalone monsters and was even included in an official Lego X-Files set.