Richard Biggs plays a biologist who's just fascinated with alien biology.
Adored by the Network: There was a time in the early 2000s when the Sci-Fi Channel couldn't go a week without showing at least one Tremors movie, or, more than likely, all four. This eventually led to Tremors: The Series, which was...not so beloved.
Executive Meddling: The studio suggested Michael Gross in the hopes that his Family Ties fame would benefit the movie. Producers were hesitant for that very reason because Steven Keaton and Burt Gummer are practically opposites. However, during the audition, Gross demonstrated his range and greatly impressed them. Effectively a positive example of this trope.
On that same note, Reba McEntire was also someone the studio wanted in the movie. Again, the filmmakers were impressed with her audition despite her relative inexperience in acting (Tremors being McEntire's first film role).
Old Shame: The first movie was this for Kevin Bacon at first. (Before the film's release he had a public breakdown in which he ranted to anyone who approached that his career was over because he was starring in a "stupid movie about killer worms".) He's since lost this attitude, especially given that Tremors is now seen as something of a classic (and has an 89% "fresh" rating on Rotten Tomatoes"), but it was his embarrassment at being in a "stupid worm movie" that kept him out of any of the sequels.
The Other Darrin: Susan Chuang played Jodi Chang in Tremors 3, but was replaced by Lela Lee for the TV series. Charlotte Stewart played Nancy Sterngood in the first and third films, but was replaced by Marcia Strassman in the series. (According to Word of God, the latter was because Stewart had landed a commercial deal and her contract wouldn't permit her to be on the series at the time.)
Otherwise refreshingly averted. Robert Jayne plays Melvin Plug in the first and third film and as a recurring role in the series, and both Tony Genaro as Miguel and Ariana Richards as Mindy Sterngood appear in the first and third films. However, Mindy was later played by Tinsley Grimes in her one appearance on the series.
Screwed by the Network: The TV series. Stiffed in terms of promotion, shown completely out of order, and then canceled out of spite when it got good ratings anyway.
The series was also filmed at the same time as Tremors 4, which meant that Burt had to be left out of the show at times.
Vindicated by Cable: The first movie barely made more than its budget at the American box-office (though made an extra $30 million worldwide). However, it was a huge hit on video and also did well on TV, leading to the sequels and the TV series.
What Could Have Been: Had a second season of the series come to pass such proposed developments would've included: more about the origins of Mixmaster; Mixmaster-affected bugs that eat only rubber; Burt trying his hand at online dating and meeting someone... only to learn it's Nancy; Larry taking more of a role in helping defend the town; and Rosalita revealed to have a shady past.
Concepts for a TV series were developed during production of Aftershocks. This series would've cast Val and Earl as monster hunters facing a variety of creatures. Some of the details are available here. Of interest, El Blanco, the Killer Shrimp from "Water Hazard" and the "fly fishing" method from "Blast from the Past" were originated there.
A proposed fifth movie would've been another Sequel Goes Foreign, with Burt traveling to Australia.