While playing superheroes, Spider-Man (played by Maxfield) discovered Swamp Thing's (played by Bill) weakness.
It wasn't Krypotnite. It was not the color yellow. It was not water or fire.
It was a swift punch in the nuts.
It is also the weakness of Solomon Grundy, Juggernaut, Magneto, Lex Luther, Dr. Octopus, Electro, Joker, Black Manta, General Zod, Two Face, Dr. Doom, and Sabretooth.