In the swamps of Louisiana, Doctor Alec Holland works with his sister Linda on a top-secret bio-engineering project to create a plant/animal hybrid capable of thriving in extreme environments. Government agent Alice Cable arrives just as Holland makes a major breakthrough, and begins to develop feelings for him. However, a paramilitary group led by the evil Dr. Anton Arcane, who is obsessed with immortality, kills Linda while trying to steal the formula for their own purposes. During the attack, Alice escapes and Alec is covered in chemicals, caught on fire, and runs screaming in the swamp, presumably to die. However, he returns as a monstrously mutated plant creature. As the Swamp Thing, Holland battles Arcane's forces to protect Cable, and eventually takes on Arcane himself, also mutated by the Holland formula.Ray Wise as Alec Holland
Adrienne Barbeau as Alice Cable (a female version of Matt Cable but in place of Swamp Thing's comic book love interest Abby Arcane, who however appears in the sequel)
Louis Jourdan as Anton Arcane
Dick Durock as Swamp Thing
David Hess as Ferret
Nicholas Worth as Bruno
Don Knight as Harry Ritter
Al Ruban as Charlie
Ben Bates as Arcane Monster
Nannette Brown as Dr. Linda Holland
Reggie Batts as Jude
Mimi Craven as Arcane's Secretary (as Mimi Meyer)
Karen Price as Karen
Bill Erickson as Young Agent
Dov Gottesfeld as Commando
Tommy Madden as Little Bruno
Garry Westcott as Louis Jourdan's Stand-in and Stuntman
Filming occurred primarily on location in Charleston, South Carolina, and nearby Johns Island. Craven was very proud in delivering the movie on time and on budget at $2.5 million.
Swamp Thing received generally average to positive reviews from critics, with the movie review aggregator website Rotten Tomatoes retroactively giving the film a score of 64% based on 33 reviews. Roger Ebert gave the film three out of a possible four stars, saying "There's beauty in this movie, if you know where to look for it."
Author John Kenneth Muir notes that Swamp Thing differs in many respects from Craven's usual work, in that Craven's intent was to show the major Hollywood studios that he could handle action, stunts and major stars. Craven substituted his usual focus on the problems of the family and society for pure entertainment. Nevertheless, Muir points out, some of Craven's usual themes and images do appear in Swamp Thing. For example, as in The Last House on the Left (1972), and The Hills Have Eyes (1977), Craven shows a close connection between the landscape and his characters. The film was adapted in comic form as Swamp Thing Annual #1.
PopMatters journalist J.C. Maçek III wrote "As much fun as this film can be (and it often is), it's equally often difficult to ignore that Swamp Thing ultimately is, at core, a rubber-suit monster movie."
In August 2000, Metro-Goldwyn-Mayer released the film on DVD in the United States. Though the DVD was labeled as being the PG-rated, 91-minute cut of the film, MGM had inadvertently used the 93-minute international cut of the film which contained more nudity and sexual content than the US theatrical cut. In May 2002, a Dallas woman rented the disc from a Blockbuster Video store for her children and reported this discrepancy. MGM recalled the disc and reissued it in August 2005, with the US theatrical cut as originally intended.
Swamp Thing was released in a Blu-ray Disc/DVD combo pack by Shout! Factory on August 6, 2013. The set features the 91-minute cut of the film presented in high definition anamorphic widescreen format, along with bonus content including interviews with Adrienne Barbeau, Len Wein, and Reggie Batts, as well as commentary tracks with Wes Craven and makeup artist Bill Munn.
A low-budget sequel entitled The Return of Swamp Thing was released in 1989.
In 2009, Joel Silver announced plans to produce a reboot of the Swamp Thing film franchise from a story written by Akiva Goldsman. In April 2010, Vincenzo Natali was confirmed to direct, but on May 12, 2010, Vincenzo Natali decided to delay the Swamp Thing reboot to pursue other projects.