The "Flukeman" suit dissolved in water, forcing special effects artist Toby Lindala to reconstruct the suit each day.
The look of the "flukeman" appears to be strongly based on a birth defect known as harlequin-type ichthyosis. Babies with this birth defect are born with extremely dry, cracked skin resembling scales or armored plating due to a defect in the gene that directs skin cell division, causing them to divide and grow far faster than the body's ability to shed them, also causing their mouth to be pulled into a wide, circular gape due to the tightly pulled skin, and giving them an "alien" appearance. In all except a tiny handful of cases, babies born with it don't live longer than a few days (a week at the most) because the skin cells divide so rapidly, their bodies simply can't consume and process enough nutrition to keep up with cellular division.
The Flukeman suit took 6 hours to put on. At one point, Darin Morgan had to wear it for 20 consecutive hours. He had to relieve himself whilst wearing the suit.
While Scully reads the newspaper left under her door a news article is briefly seen announcing the death of Nirvana lead singer Kurt Cobain. Cobain's death occurred earlier that year.