Gillian Anderson's character Scully was supposed to eat a cricket in front of Mulder. After Scully picked it up, the scene was to be stopped so a candy bug could replace the real one. However, before "cut" could be called, Anderson immediately placed the real bug in her mouth and ate it, and it stayed in the final cut. David Duchovny's off-screen gross out can be seen in one of the many "Making of the X-Files" featurettes.
The setting, Gibsonton, Florida, is a real town in Florida. It is mainly populated by circus performers, who originally resided there in the circus off-season. This circus performer population is due to its proximity to the Ringling Bros. Circus winter home in Tampa and Sarasota and due to its liberal zoning laws that allowed the storage of such things as elephants and circus trailers on front lawns.
The condition that the character Jerald Glazebrook suffered from, harlequin icthyosis, is a real genetic condition. Epidermal skin cells divide so rapidly that the outer-layer skin cells cannot be shed fast enough, thus causing the skin to develop severe diamond-shape cracked scales like that of the Glazebrook character. The disease is almost always fatal within 2-7 days of birth: most infant victims die of starvation due the body's inability to cope with the high nutritional demands of such rapidly dividing skin cells or due to massive systemic infections of the exposed cracks. However, in a dozen cases worldwide, sufferers have managed to survive into adulthood. A topical solution of Retin-A or other retinosteroids usually help. But sufferers must always be careful to avoid infection, because even a simple skin infection can easily be life-threatening. Sufferers must also maintain a strict high-calorie diet rich in lean proteins.
While this episode is set in Florida, it was actually filmed in White Rock, British Columbia, Canada during the winter. The production team removed all the snow from the park to make it look like Florida, and The Enigma actually swam in a river that was freezing cold.
Jim Rose and The Enigma are part of an actual circus, The Jim Rose Circus, founded in Seattle by Jim Rose in the early 1990s. They came to prominence as The Jim Rose Circus Sideshow while performing on the second stage at the 1992 Lollapalooza festival .