Swamp Thing

Swamp Thing is a DC Comics character created by Len Wein and Berni Wrightson. Once a humble biogeneticist, Alec Holland was caught in an explosion in his hidden lab. Burning and coated in his bioregenerative compound, he stumbled outside and into the swamp. There he either fused with the plant life, or he died and the regenerative compound created a plantlife doppelganger, depending on the writer of the story. Either way the Swamp Thing became an avatar of plant life worldwide.

In addition to the comic, and its most well known arc penned by Alan Moore, there have also been two Swamp Thing movies and an unexpectedly long lived television show.

Abigail Arcane
Swampy first met Abigail after being summoned to europe by his most aggressive adversary, Anton Arcane. Anton would go on to fight Swamp Thing time and again, finding new ways to rise from the grave and bring suffering to him and those around him, including Anton's niece Abigail. Abigail would travel with Matt Cable, a friend of Alec Holland's who was tracking the monstrous Swamp Thing, and eventually marry him as well. Years later the marriage would prove to be a deeply unhappy one, with Matt turning to the drink and a magical talent for illusions he had discovered. After Matt fell into a coma following one of Anton's plots Abigail would confess her love for the Swamp Thing, which Swampy returned.

In the New 52 Abigail is rudely pulled out of her idyllic life when her Swamp Thing suddenly vanishes, its spirit returned to the now revived actual Alec Holland. Distancing herself from the Swamp Thing also reveals to her that, in the same way that Swamp Thing is the avatar of the Green, Abigail was destined to be the avatar of the Rot. In order to save Alec she submits to the army of rot led by Seethe, becoming his bride. Swamp Thing is able to destroy the hold Seethe had over her, restoring her mind and letting her sink Seethe's entire army into the ground through the use of her powers.

Almost immediately afterwards Anton appears, in this universe both Abigail's father as well as an elemental force of Rot who has killed the avatars of Green and Red for a century, including the original incarnation of Alec Holland. After Swamp Thing is cast into the future of the Rotworld storyline Anton tracks Abigail down and kills her, assuming her title as champion of the Rot. When the Swamp Thing travels back in time to shortly before this he is able to stop Anton, but not even his power, as well as the assistance of the now helpful parliament of Rot, can defeat Anton. In order to stop her father Abigail assumed the responsibility of the avatar, letting her humanity die and forever making her love with Swamp Thing impossible. Their battle won, the lovers say their farewells and go their own ways.

Phoebe
In Saga of the Swamp Thing #40 Swamp Thing is called to Kennecook by John Constantine to look into unusual events there. Centuries beforehand the local nation confined their women to a special room in that area during their menstruation. In modern times Phoebe and her husband live in a house built on that site. During the full moon Phoebe finds herself overcome by the power of the spirits, transforming into a werewolf and taking her anger out on the hardships of her life. As much as she wants to slay her husband, however, she finds that she does not have the will to do so. She enters the town, destroying the landmarks of her stable, stale life, until she finally sees a way to relieve herself of her crushing monotonous life: a display of silver steak knives. After impaling herself on the display the beast leaves her, letting her die peacefully.