The main series characters are introduced. Swamp Thing first meets 11-year-old Jim Kipp whose divorced mother, Tressa, is visiting her mother’s home. Jim encounters Humphrey, a dwarf who has escaped from the evil Dr. Arcane. Tressa struggles with raising her son as well as finding her magic powered necklace, called “the emerald heart” in the swamps.
Dr. Arcane transforms his partner in crime into the "living image" of Swamp Thing's lost spouse in hopes of tricking him into revealing the formula for the bio-restorative recipe, which is intended to modify the DNA and stop aging.
Thugs working for Arcane kidnap Jim. Arcane takes one of his 'creations' into the swamp and is met by Swamp Thing who objects. The creature escapes and Arcane is killed, but must be “revitalized” in order for Swamp Thing to save Jim.
Jim and Oboe sneak out on a midnight visit to the swamp and are resolute to see a mystical spirit called the Swamp Maiden who appears only once every three years. Jim plans to take pictures of her although both have been warned not to touch her. An unknown man offers to buy the pictures that Jim might take.
Veteran actor Roscoe Lee Browne plays a ""Ogun"" which is a voodoo priest whom Archane employs to overcome Swamp Thing.
Arcane's protégé, named Crown Prince, is experimenting with hatred pheromones and his latest batch is released into the swamp air and Tressa is infected with the chemical agent which leads to all townspeople that she comes into contact with wanting to kill her. Only an intervention from Swamp Thing as well as Jim can cure her.
Swamp Thing is overcome by toxic waste and falls unconscious where he is found by two clean up men and is sold to a carnival freak show ran by a cruel man in league with Arcane. Jim stumbles by and sees the weakened Swamp Thing in a cage, and he is its only hope to get him back to the swamp to recover.
Swamp Thing is teaching Jim about endangered planets in the swamp when they come upon an area Swamp Thing refused to explain or let Jim go into that looks intriguing to a young boy's fancy. Jim being the inquisitive bash young boy he is, can't resist returning to have a look. During his brief visit he is bitten by a venomous insect created by Archane.
A thief on the run from his female accommplice choses the swamp as his hiding place for a fortune in stolen cash and Jim's house as his final stop.
Jim is feeling lonely and tries to make a new friend when he meets a mysterious young girl in town, named Lily, who invites herself into Jim and Tressa‘s home, and who carries a dark secret.
One of Archane's failed experiments, a man-bird, comes looking for vengeance during the funeral for Jim's grandmother and only Swamp Thing as well as an encounter with danger involving Jim can redeem “Falcon Man”.
Jim and Tressa may have to leave the swamp after a lawyer delivers a notice of eviction. But they are unaware that the lawyer is in league with Dr. Arcane whom plans to use the property to expand his lab. Only through dreams does the late Tressa’s mother communicates to her with clues to find her real will guarded in the swamp.
Arcane captures Jim and sells him into slavery after the boy is witness to the evil doctor's hideous transformations of men into monsters and the local sheriff is in on the plans. Jim’s 17-year-old half-brother, Will, arrives to investigate Jim’s disappearance and teams up with Swamp Thing to find Arcane’s secret lab, but neither are aware that Jim is already gone from the country and the sheriff is one step head of their moves.
A runaway synthetic human from Dr. Woodroes lab, Abigail is seen running through the street from an exploding boat by Will who befriends her. Meanwhile a baby is swept away by the waters of the swamp from the same explosion into the arms of the Swamp Thing.
Swamp Thing is framed by one of Arcane's mutants for murdering a local District Attorney who was on to Arcane for his latest nefarious plans. Meanwhile, Abigail continues to try to weave herself into Will’s life as well as persuade him to expand his boundary of knowledge.
When Tressa accompanies her old college roommate, Ilene, and her daughter on an overnight camping trip, Arcane traps Ilene and her daughter behind an invisible force shield and only Swamp Thing can rescue them when Tress is disabled by a snake bite and both Will and Abigail are powerless to do anything.
Arcane trades bodies with Swamp Thing after setting a trap using Will as bait. While Swamp Thing deals with being human for the first time in years and interacting with an unknowing Will, Tressa, and Abigail, he must find a way to switch back within 24 hours or the change will become permanent.
Tressa accidentally stumbles across Arcane's latest model of two robot henchmen, called Watchers, who are hunting down Abigail to erase any evidence of the late Dr. Woodroe’s test tube experiments. Meanwhile, Will decides to throw Abigail a birthday party when she does not remember her birthday since she never had biological parents.
Will's estranged father shows up looking for a rare white orchid that Arcane and his henchman, Graham, has nefarious plans for. Tressa struggles with her romantic feelings for him, and Abigail, working in the town’s greenhouse, succumbs to the poisonous fumes of a certain red orchid, and only the healing powers of the white orchid can save her.
Arcane experiments with Dr. Holland's formula by murdering a local man who comes back from the dead with severe side effects; a single touch can drain a person‘s life energy in which Will becomes infected and pushes away Abigail. Only Swamp Thing can come to anyone‘s rescue.
Under pressure from his superior, the shadowy General Sunderland, Arcane experiments with artificial earthquakes when he hires a hot female engineer, named Sienna, to create earthquakes at this latest weapon which leads to a personal conflict between Arcane and Sienna over the test runs, and it also lands Swamp Thing in a bind when he becomes trapped in the underground facility and weakening fast from lack of sunlight. Elsewhere, after Will goes out of town with Dr. Hollister to shop for a new truck, Abigail finds herself helpless when Tressa becomes pinned under the fishing pier during another aftershock and the rising river water threatens to drown her.
Tressa and Abigail are taken hostage by a man with a score to settle with Arcane, and whom has developed an environment destroying weapon called the Prometheus Parabola, capable of destroying the swamp and Swamp Thing intervenes in the literal shoot-out war at Tressa’s house to see that both sides do not activate the weapon while Will tries to rescue Tressa, Abigail, and Dr. Hollister from harms way.
Archane buys a rare book of voodoo spells and while summoning Baron Samedi he is possessed by evil spirits. The book is actually a trap for Archane by the daughter of the Ogun Duchamp who seeks revenge for Jim Kipp. On Archane's side is Duchamp's son who has taken his father's place.
A self-proclaimed psychic comes to the swamp in search of Alec Holland with a message from his dead wife Linda. She also reveals that Jim is still alive and will be heard from soon.
A cold paralyzing cloud of mist from the swamp attacks the town. In the face of this threat, Abigail makes the ultimate sacrifice to save a little boy.
Will's past as a juvenile delinquent comes back to haunt him when three of his former gang that he knew back in Philadelphia come to town to persuade him to help them in a robbery.
A scientist from Alec Holland's past is employed by a businessman who claims he wants to build a recycling plant near the swamp. His real motives are to build a resort in collaboration with Archane.
Will starts dating a girl from a carnival. Her boss who is manipulating the young carnies wants to sacrifice Will to ""the forces of darkness"" in a scam to keep his young work force in line.
After being electrocuted while at the controls of his latest scientific experiment, Arcane has a near-death experience where he is put on trial and gets judged for all his past misdeeds with Tressa as the judge and Will as his lawyer and both the prosecutor.
Ian James is an unscrupulous anthropologist who releases poisonous tree frogs in the swamp to further promote his documentary film of the swamp while he charms his way into Tressa’s life while Will is as always suspicious to James’ true nature especially when James plans to catch on film the so-called Swamp Thing to further advance his career.
Nathan Stone is a heavy mental musician staying alone in the Kipp boarding house where Swamp Thing terrorizes him with a series of mind games as he seeks to teach the shallow and egotistical punk rock star to take responsibility for his wicked lyrics that has led to the suicide of two teenage fans.
Will is taken hostage by two men whom are greedy explorers whom force him to help them find the location of a mystic Mayan temple in the swamp housing buried treasure which is guarded by two vengeful Mayan ghosts.
Ann Fisk returns to the swamp, intent on finding out if Swamp Thing is really the man, Alec Holland, whom she knew all those years ago and then tries to find a way to transform the creature back into the human scientist she once knew. But complications set in when two revenge-seeking redneck brothers take Ann as well as Arcane and his henchman, Graham, hostage and Swamp Thing is torn over using his powers to save them aware that his chance to become human again will be lost.
A recent storm in the swamp uncovers a car wreck from ten years ago,including the married couples ghosts that think only hours have passed.
A young loner who believes he is a vampire is accused of murdering his mother's boyfriend.
After seemingly having no interest for so many episodes what happened to Jim, Tressa is suddenly in Peru and sidetracked by a voice from her past on a radio.
Return to those thrilling days of the old west in guilt ridden dreams, when Arcane is allowed to hunt a man with the full knowledge of the sheriff.
What happens the swamp itself is no longer an ally to Swamp Thing? The answers lay with a man called Mephisto.
Archane has created a poison engineered to specifically target Swamp Thing's genetic code. Ann has discovered a method of temporarily changing Alec back to human form.
Encountering two men already dead in the swamp is nothing particularly new for Will, but the fact they are from the civil war era is. Can Will solve this mystery of the swamp and find peace for two soldiers?
Arcane finally resurrects his dead wife only to discover he's been duped by Sunderland. The body he's been lording over really belongs to a stripper named Kitty. Which sends Arcane on a rampage of revenge, that turns bitter sweet when he finds his true wife.
Arcane's genius mentor, Carl Mirador, has died. Using an experimental brain cell transfer, Arcane transfers all of Mirador's knowledge into his own brain. This does not go well as Mirador physically takes over Arcane’s mind and body. Meanwhile, Will meets and falls for Mirador’s granddaughter, Dana.
Arcane's rival, Carla Jeffries (Tyne Daly) takes over his business. Swamp Thing discovers that she's a much more formidable enemy than Arcane ever was. Will he, Arcane and Graham put their differences aside to oust Carla?
Swamp Thing is wounded and being tracked down by mercenaries hired by Arcane. He makes his way to Dr. Ann Fisk's lab and is transformed back into Alec Holland. Afterward he is still wounded and aided by Tressa Kipp who finally learns the truth about Swamp Thing.
A wealthy hunter stalks and wounds a rare hawk for a trophy. Afterward the swamp takes Will into it's confidence and Will sees the swamp as he never has before.
The body of a dead man leads Swamp Thing to Archane and Gen. Sunderland.
A chemical plant causing toxic damage to the swamp is the key to a darker future.
Three convicts escape from prison in search of loot from a Las Vegas heist buried in the swamp. One by one they learn the justice of the swamp.
Two young co-eds looking to perform a magic ceremony called the test of Shabalba that will grant them three wishes use Will as a reluctant guide.
Can Swamp Thing save his friend Will from charges of a murder is didn't commit versus the ambitions of a corrupt District Attorney?
When an elderly woman, named Irma Swanson, who knew and befriended Swamp Thing, dies, her estranged daughter, Cathy, comes to town for her funeral. Swamp Thing and the spirit of Irma then show Cathy the past of Irma’s troubled life in order for Cathy to make amends meet.
When a stranger comes to swamp with evil designs of his own upon Swamp Thing's blood, Archane becomes involved.
Will becomes involved with a couple who hold a map that Archane has a keene interest in obtaining.
When the swamp stalks Archane in the form of a panther, an ecological message is the overtone about unsafe modes of power encroaching on nature and how she strikes back. Leaving a forboding and chilling message when even Swamp Thing is powerless.
Swamp Thing gets addicted to hallucinogenic iguana eggs which makes him live out a fantasy with Ann. But the effect causes bad luck with Will when he comes into contact with one of them and ends up a prisoner in Arcane’s lab who is determined to find the nest of rare eggs himself for personal use.
Oliver Duncan awaits death in a hospital while Archane plots to gain his former teachers secrets.