John Constantine is a DC comics character.
An antihero , or antiheroine , is a protagonist who lacks conventional heroic qualities such as idealism , courage , or morality . Constantine is an American television series developed by Daniel Cerone and David S. Goyer for NBC , featuring the DC Comics character John Constantine . John Constantine . The character first appeared in Swamp Thing Vol . The Swamp Thing is a fictional character in the DC Universe . He first appeared in House of Secrets # 92 ( July 1971 ) in a stand-alone horror story set in the early 20th century .