It stars Ben Kingsley, Michael Madsen, Alfred Molina, Forest Whitaker, Marg Helgenberger, and Natasha Henstridge in her film debut role.

The film's plot concerns a motley crew of scientists and government agents who try to track down Sil (Henstridge), a seductive extraterrestrial-human hybrid, before she successfully mates with a human male.

The effects combined practical models designed by Giger collaborator Steve Johnson and XFX, with computer-generated imagery done by Richard Edlund's Boss Film Studios.

Inspired by the second transmission, a government team led by Xavier Fitch commissions a genetic experiment meant to create a female alien/human hybrid organism under the belief that she would have "more docile and controllable" traits.

Using her superhuman strength and intelligence and regenerative capability to evade capture, Sil matures rapidly into her early twenties and travels to Los Angeles, where she kills several people to prevent them from alerting authorities and disguises herself.

Secretly returning to Carey's home to spy on Fitch, Sil reads his lips and determines he and his team plan to stake out a nightclub to find her.

[4] Writing for the Journal of Popular Film & Television, Susan George authored a paper that dealt with the portrayal of procreation in Species, Gattaca and Mimic.

[5] George further states that a recurring theme in science fiction films is a response to "this kind of powerful female sexuality and 'alien-ness'" in that "the feminine monster must die as Sil does at the end of Species".

[4] A five-year investigation into accounts of the chupacabra, a well known cryptid, revealed that the original sighting report of the creature in Puerto Rico by Madeline Tolentino may have been inspired by the character Sil.

[6] According to Virginia Fugarino of Memorial University of Newfoundland writing for the Journal of Folklore Research, Radford found a link between the original eyewitness report and the design of Sil in her alien form, and hypothesized that "[Species], which [Tolentino] did see before her sighting, influenced what she believes she saw of the chupacabra".

[4] Having read an article by Arthur C. Clarke about the insurmountable odds against an extraterrestrial craft ever locating and visiting Earth, given that stellar distances are great, and faster-than-light travel is unlikely, Feldman started to think that it was "unsophisticated for any alien culture to come here in what [he]'d describe as a big tin can".

After coining the name "Sil", Feldman initially thought of forming an acronym, but in the end chose only the three-letter name after learning about the codons of the genetic code, which can be represented in groups of three letters.

Giger had envisioned more stages of Sil's transformation, but the film only employed the last one, where she is "transparent outside and black inside—like a glass body but with carbon inside",[14] with XFX doing the translucent skin based on what they had done for the aliens of The Abyss.

[14] Richard Edlund's Boss Film Studios was hired for over 50 shots of computer-generated imagery, which included one of the earliest forms of motion capture effects.

Using a two-foot-high (60 cm) electric puppet that had sensors translating its movements to a digital Sil, Boss Films managed to achieve in one day what would have once taken as much as three weeks with practical effects.

The designer felt that horror films frequently held some final confrontation with fire, which he considered old-fashioned and linked to medieval witch trials.

[8] Filming happened mostly in Los Angeles, including location shooting at Sunset Strip, Silver Lake, Pacific Palisades, the Hollywood Hills and the Biltmore Hotel.

Id Club, the nightclub featured in the film, was built within Hollywood's Pantages Theater, while the hills above Dodger Stadium near Elysian Park were used for the car chase and crash where Sil fakes her death.

For the opening scenes in Utah, the Tooele Army Depot dubbed as the outside of the research facility—the interiors were shot at the Rockwell International Corporation laboratory in California—and a Victorian-era train station in Brigham City was part of Sil's escape.

The tunnels were built out of structural steel, metal rod, plaster and concrete to endure the fire effects, and had its design based on the La Brea Tar Pits, with Muto describing them as "just the sort of place in which a creature from another planet might feel at home".

[25] James Berardinelli gave the film 2½ out of 4 stars, stating that "as long as you don't stop to think about what's going on, Species is capable of offering its share of cheap thrills, with a laugh or two thrown in as well".

[26] Owen Gleiberman of Entertainment Weekly found the film lacking in imagination and special effects, also commenting that Alfred Molina "sport[s] a haircut that's scarier than the creature".

[27] Variety's review of the film described it as a "gripping if not overly original account of an extraterrestrial species attempting to overwhelm our own" and that Ben Kingsley and other lead actors "have only two-dimensional roles to engage them".

[29] Mick LaSalle, writing for San Francisco Chronicle, was notedly less enthusiastic, quipping that if "Species were a little bit worse, it would have a shot at becoming a camp classic".

The book gives several in-depth details about the characters not seen in the film, such as Sil's ability to visualize odors and determine harmful substances from edible items by the color.

Species II received overwhelmingly negative reviews from critics, garnering a 9% approval rating at Rotten Tomatoes,[38] and Madsen denounced it as a terrible film.

[43] The film's plot starts where Species II ends, revolving around Sunny Mabrey's character Sara, the daughter of Eve, reared by a doctor played by Robert Knepper.

Two out of six critics mentioned on Rotten Tomatoes gave it a positive rating,[44] with DVD Talk's reviewer noting that it is "a more cohesive and sensible flick than [Species II] is, but ultimately, it's just a lot of the same old schtick", while Film Freak Central called it "amateurish" and "vapid".