Bissette, Steve - Swamp Thing, issue 40, page 4 (Sep 1985)

Swamp Thing was created by writer Len Wein and artist Berni Wrightson. He first appeared (as scientist turned Swamp Thing, Alex Olsen) in House of Secrets #92 (July 1971) in a stand-alone horror story set in the early 20th century. The character then returned in a solo series, set in the contemporary world and in the general DC continuity. The character is a humanoid mass of vegetable matter who fights to protect his swamp home, the environment in general, and humanity from various supernatural or terrorist threats. Swamp Thing can inhabit and animate vegetable matter anywhere (including alien plants, even sentient ones) and construct it into a body for himself. As a result, bodily attacks mean little to him. He can easily re-grow damaged or severed body parts, and can even transport himself across the globe by leaving his current form, transferring his consciousness to a new form grown from whatever vegetable matter is present in the location he wishes to reach.

After the success of the short story in the House of Secrets comic, the original creators were asked to write an ongoing series, depicting a more heroic, more contemporary creature. In Swamp Thing #1 (October 1972), Wein and Wrightson updated the time frame to the 1970s and featured a new version of the character: Alec Holland, a scientist working in the Louisiana swamps on a secret bio-restorative formula "that can make forests out of deserts". Holland is killed by a bomb planted by agents who want the formula. Splashed with burning chemicals in the massive fire, Holland runs from the lab and falls into the muck-filled swamp, after which a creature resembling a humanoid plant appears some time later.

The creature, called Swamp Thing, was originally conceived as Alec Holland mutating into a vegetable-like creature, a ‘muck-encrusted mockery of a man’. However, under writer Alan Moore (who took over the writing of the series in issue #21 in February 1984, at that time titled Saga of the Swamp Thing), the character was reinvented as an elemental entity created upon the death of Alec Holland, having somehow absorbed Holland's memory and personality into itself. He is described as ‘a plant that thought it was Alec Holland, a plant that was trying its level best to be Alec Holland’.

In Swamp Thing #33 (February 1985), Alan Moore attempted to reconcile the two versions of Swamp Thing with the revelation that there have been many previous incarnations of Swamp Thing – perhaps hundred - prior to the death and "rebirth" of the Alec Holland incarnation. Further, all versions of the creature since the dawn of humanity were designated defenders of the Parliament of Trees, an elemental community also known as ‘the Green’, that connects all plant life on Earth.

In conjunction with gorgeous art by Steve Bissette and John Totleben, Moore's Swamp Thing had a profound effect on mainstream comic books. It was another character revival by Moore (his first being Miracleman) based on stretching the boundaries of not just the character, but also the genre within which he was working. He broadened the scope of the series to include ecological and spiritual concerns while retaining its horror-fantasy roots.