Alec Holland's Bio-Restorative Formula

Alec Holland was working on a revolutionary formula that would regenerated damaged plant tissue when he was burned alive in an attack. This formula fell into the swamp, along with Alec Holland's dead body, and Swamp Thing was born. Swamp Thing gets his powers of regeneration, and probably his very existence, from this formula.

Woodrue's Research File on Swamp Thing

In the course of his research, Woodrue discovers that Swamp Thing is not Alec Holland at all, but merely plant material that has absorbed Alec Holland's consciousness. This revelation, as read from Woodrue's report, causes Swamp Thing to go mad and attack the old man in issue #21.

Flexi-Flesh

Jason Woodrue, aka the Floronic Man, uses a can of Flexi-Flesh to apply realistic flesh to his otherwise plant-like body. By using this compound he is able to pass for a human botanist.

Swamp Thing's Tuber