Green Lantern or John Stewart is an African-American adult male. He has a musclebound physique and wears the typical Green Lantern attire with a glowing symbol of such on his chest and obviously the green power ring. He has light blue-ish eyes, short black hair with grey on the sides, and black eyebrows. When using his power ring, his entire body is covered in a light green aura.
Green Lantern was first seen alongside his Justice League team mates during "Devil's Snare" after Gotham City was overtaken by evil trees created by Scarecrow using Poison Ivy's pheromones. He used his Green Lantern Ring to construct a sword out of bright green energy which he used to slice up the trees. The League initially thought that Harley's Crew were responsible for the attacks due to Poison Ivy's ability to control nature, however, they soon proved their innocence. Before they could find out who was really responsible, Queen of Fables showed up and trapped them all in her story book as revenge for imprisoning her in a U.S. tax code book many years ago.
They were all freed in "A Fight Worth Fighting For" after Harley Quinn tracked down the book in order to get their help stopping Doctor Psycho from taking over the city with his mind-controlled Parademon army. Green Lantern seemed relieved to be freed from the prison although not as traumatized by the experience as his peers. After Batman brought them all up to speed, Green Lantern left.
He, like all the Justice League members, are there to help solves disasters of all sorts, such as any and all evil efforts by the Legion of Doom. He seems to be extremely confident in his own powers, not having to think twice before slicing the fear toxin trees apart with ease. He also appears very stoic, seemingly being the Justice League member least traumatized after being trapped in the storybook.