Abby Arcane returns home to Marais, Louisiana,[1] to investigate a deadly swamp-borne virus, where she develops a bond with disgraced scientist Alec Holland.

Mark Verheiden and Gary Dauberman were attached to write the first episode of the series and executive produce alongside James Wan and Michael Clear.

[17] In September 2018, Crystal Reed and Maria Sten were cast in the main roles of Abby Arcane and Liz Tremayne, respectively.

[10] More series regulars were later revealed, with Jeryl Prescott cast as Madame Xanadu,[8] Virginia Madsen as Maria Sunderland,[4] Will Patton as Avery Sunderland,[9] Andy Bean as Alec Holland with Derek Mears as the Swamp Thing,[5] Henderson Wade as Matt Cable,[6] and Kevin Durand as Jason Woodrue.

The website's critical consensus reads: "By leaning into the horror of it all, Swamp Thing swims deep into the trenches of this strange world and returns with a scary good TV show.

[34] David Griffin, writing for IGN, said the series properly "honors the comic book origins" of Swamp Thing and praised the performance of Crystal Reed, Virginia Madsen, and Will Patton, as well as the film-making style of Wiseman.

[35] Daniel Fienberg of The Hollywood Reporter praised the creepy atmosphere and found the cast performances to be strong enough to carry episodes even when the monster was not on screen.

[36] In a more mixed review, Kevin Yeoman, writing for Screen Rant, approved of the "nausea-inducing practical effects" reminiscent of John Carpenter's The Thing but criticized the writing and pacing and found the decision to not reveal Swamp Thing until the final moments of the pilot episode to be frustrating.

[37] Joel Keller of Decider found the horror elements made up for generic characters and an uninteresting mystery plot line.

[41] Swamp Thing, as depicted in the series, makes a cameo appearance in the Arrowverse crossover event "Crisis on Infinite Earths" through archival footage of Mears as the character.