AKA: Alec Holland
- Anthropomorphic Personification: Of Nature
- Badass Bookworm: Well, Alec used to be a scientist. He delivered a Curb-Stomp Battle to Batman. Nuff says.
- Becoming the Mask: He isn't really Alec, just a plant elemental who assimilated Alec's memory and personality.
- Berserk Button: Don't touch Abby. Really, just don't.
- Beware the Nice Ones: Despite his monstrous appearance, he really isn't that bad of a person. We still advise against pissing him off however, as he is capable of plant-based rampages on par with Poison Ivy's, if not worse.
- Chest Insignia: After being brought back by the White Light, the White Lantern symbol glows on Swamp Thing's chest.
- Creepy Good: See Horrifying Hero.
- Dead All Along: After the retcon.
- Elemental Embodiment: Of Nature.
- Gaia's Vengeance
- Horrifying Hero: He is a mass of plants assuming a vaguely humanoid form, several times taller than a regular human being and living in a Swamp. Still pretty much a good guy.
- Interspecies Romance: With Abby.
- Light 'em Up: Thanks to the whole Brightest Day shenigans.
- Nature Hero: He is nature.
- Plant Person: Just look at the picture.
- Super Power Lottery:
- Bizarre Alien Senses: In the "vegetable sex" scene, Abigail temporarily experiences Swamp Thing's ability to sense life force, and perceives the wetlands as a shimmering field of glowing vegetation, dotted with bright life-sparks of animals.
- Elemental Powers
- Green Thumb: Obviously, and he is a good contender for the strongest case of this power in the whole DCU. His control over plant life is strong enough that he can transform the entirety of Gotham into a jungle.
- Healing Factor: Up to Eleven; he can rebuild his body out of any mass of vegetation, even if it has been completely blown up. This borders on Resurrective Immortality.
- Super Strength: His physical strength is just as impressive as his size would make you expect.
- Tomato in the Mirror: He never was Alec Holland. He's just a ghost in weeds.
- Averted in the New 52.
Abby Arcane Holland
Swamp Thing's Love Interest (later wife), and Dr Arcane's niece.
- Boyish Short Hair: In the New 52.
- Distaff Counterpart: Of a sort to Swamp Thing as the Avatar of the Black.
- Happily Married: Eventually, to Swamp Thing.
- Interspecies Romance: With Swamp Thing. This was actually made a plotpoint once, as she was arrested for essentially marrying a plant. Swamp Thing didn't react well.
- Rescue Romance: She fell in love with Swamp Thing after he rescued her.
- Mad Scientist's Beautiful Niece: To Arcane.
- Mystical White Hair: She is best-recognizable by her white and black hair.
- Skunk Stripe: Inverted. She has white hair with a black stripe.
- Psychic Powers
Abby's uncle and Swamp Thing's Arch-Enemy, Arcane is an Evil Sorcerer Mad Scientist obsessed with gaining immortality. To this end, he has tried several times to get his hands on the Swamp Thing's body.
- Alliterative Name: Anton Arcane.
- And I Must Scream:
- While in Hell, spiders lay eggs inside his body that hatch and eat their way out, causing him awful pain for eternity. To make things worse, the whole thing include a case of Year Inside, Hour Outside.
- Later, The Parlment of Decay punishes his misuse of the Rot by trapping him a place of peace and life where death doesn't exist... which, considering his obsession with creating a place of endless death and decay, is torture to him.
- Arch-Enemy: To Swamp Thing. He is by far the most persistant and personal antagonist.
- Axe-Crazy: Could seriously rival The Joker as one of the most depraved, homicidal villains in the DCU. His "accomplishment" include, among others, molesting his sister as a child, experimenting on his wife, practicing a lifestyle of necrophilia, cannibalism and satanism, and once indirectly raping his own niece.
- Back from the Dead: Death seems to be more of an inconvenience, really.
- Bald of Evil: Usually despicted as bald, though there have been exceptions.
- Big Bad: By far the most prominent villain faced by the Swamp Thing.
- Demonic Possession: When he managed to escape Hell, he used this to interact with people, even possessing Matt Cable for a time.
- Disproportionate Retribution: Completely ruined his niece's life just because she turned down his request that she becomes his apprentice.
- Enfant Terrible: Even as a kid, he was a sociopath who took pleasure in hurting and molesting his younger sister. And he only got worse growing up.
- Evil Sorcerer: Skilled in many forms of magic, including necromancy, among other things.
- Evil Uncle: Doesn't even begins to describe his relationship with Abby.
- Heel–Face Turn: Though obviously, it didn't stick.
- Immortality Seeker: His main goal. Towards this end, he often plotted to steal Swamp Thing's indestructible body to inhabit.
- Joker Immunity: As noted abouve, he has been killed an incredible number of times, but he always manages to come back and torment the Swamp Thing again.
- Mad Scientist: He is a brillant enough scientist to create synthetic organic matter, which he uses mostly to create monsters or find ways to become immortal.
- Necromancer: In the New 52, he became the avatar of the Rot, the force of Decay and Death.
- One-Winged Angel: Has at several times turned himself into various kind of hulking monsters through his experiments.
- Reality Warper: Used for horrific results when he possessed Matt Cable.
- Same Character, but Different: By far one of the villains who has changed the most over the course of years, to the point it's difficult to find a picture appropriate for his page.
- Spider People: In his third appearance, he became a cybernetic monstrosity, half spider, half zombie, with one compound eye piloting a aircraft shaped like a dragonfly.
- Take Over the World: Seemingly Anton Arcane's ultimate goal. Later, he had the power to do so when he took possession of Matt Cable's body and his reality warping abilities. And during Rotworld, we saw what the world would be like under Arcane's rule.
AKA: Jason Woodrue
- Breakout Villain: He started out as a fairly minor villain from The Atom. Then Alan Moore used him for his own take on Swamp Thing, and he quickly got a boost in popularity.
- Gaia's Vengeance: Briefly attempts to do this after his contact with the Green, believing he is saving Earth from mankind by killing all non-plant life. Swamp Thing gets him out of it when he points out plants also need animals to survive.
- Go Mad from the Revelation: He once managed to use Swamp Thing's body to contact the Green. The experience drove him insane, to the point he tried to exterminate all non-plant life on Earth.
- Heel–Face Revolving Door: Briefly became a hero during The New Guardians series. He however reverted back to be a villain after the death of most of his teammates.
- Large Ham: "THERE WAS NO NOISE! THERE WAS NO SCREAMING MEAT!"
- Off with His Head!: Happened to him in Batman: Shadow of the Bat. Twice. Good thing he can heal, indeed.
- Plant Person
- Rogues-Gallery Transplant: Originally a small-time baddie who bounced back and forth between Batman and The Atom. Considering what fighting Swamp Thing did to his popularity, the change was for the best.
- Villainous Breakdown: Has several in the space of a few issues.
- Was Once a Man
- Anti-Hero: He technically is a good guy, but his motivations to do good are entirely selfish, and his methods tend to be morally ambiguous at best.
- Badass Longcoat: And a sentient one, at that.
- Breakout Character: Ended up becoming so popular he eventually got his own series.
- Jerk Ass/Jerk with a Heart of Gold
- The Mentor: to Swamp Thing.
Matt CableAbby's first husband, a government agent.
- Reality Warper: Acquired these abilities from shock treatments designed to wipe his memory clean.
- Deal with the Devil: After fatally wounded in a car crash, Arcane in the guise of a fly convinces Mat to let "help" him survive. In reality, Arcane takes over his body and uses it to exact the most twisted revenge upon Abby and Swamp Thing.
- Death Equals Redemption
- Death of the Hypotenuse: His coma and eventual death after the Arcane Saga free up Abby to openly enter a relationship with Swamp Thing guilt free.
- Inspector Javert: At first.
- Jerkass: During Alan Moore's run, Matt slides more and more into unlikable terrority, becoming colder and distant while abusing his powers to create pornographic fantasies for himself away from Abby. As such, the reader doesn't chide Abby for clearly developing romantic feelings more and more for Swamp Thing
- Transplant: He became Matthew the Raven in The Sandman.
The Parliament of Trees
The Patchwork Man
The daughter of Swamp Thing and Abby, conceived when Swamp Thing was using John Constantine's body.
- Extra Parent Conception: As noted above, she was conveived by Swamp Thing using John Constantine's body to impregnate Abby.
- Half-Human Hybrid: half-human, half-elemental.
- Mystical White Hair: Just like her mother, only without the Skunk Stripe.