Claim: John Constantine was originally a supporting character in Swamp Thing.

John Constantine -LRB- -LSB- ˈkɒnstəntaɪn -RSB- -RRB- is a fictional antihero , appearing in comic books published by DC Comics and the DC Comics imprint Vertigo . The character first appeared in Swamp Thing Vol . 2 No. 25 -LRB- June 1984 -RRB- , and was created by Alan Moore , Steve Bissette and John Totleben . He serves as the lead character of the comic books Hellblazer -LRB- 1988 -- 2013 -RRB- , Constantine -LRB- 2013 -- 15 -RRB- , Constantine : The Hellblazer -LRB- 2015 -- 16 -RRB- , and The Hellblazer -LRB- 2016 -- -RRB- .   The titular Hellblazer , Constantine is a working class occult detective and con man stationed in London . He is known for his endless cynicism , deadpan snarking , ruthless cunning and constant chain smoking , but is also a passionate humanist driven by a heartfelt desire to do some good in his life . Originally a supporting character who played a pivotal role in the `` American Gothic '' Swamp Thing storyline , Constantine received his own comic in 1988 . Pop artist Sting served as visual inspiration for the character .   A live-action film was released in 2005 entitled Constantine , in which an Americanized version of the character is played by actor Keanu Reeves . Welsh actor Matt Ryan was cast in the role of Constantine for the 2014 NBC television series Constantine , a role he reprised on The CW series Arrow , the animated film Justice League Dark and is set to reprise again in an upcoming animated continuation of his series on CW Seed .   The Hellblazer series was the longest-running and most successful title of DC 's Vertigo imprint . Empire ranked Constantine third in their 50 Greatest Comic Characters of All Time , while IGN ranked him No. 29 in their Top 100 Comic Book Heroes , and the character ranked No. 10 in Wizard '' s Top 200 Comic Book Characters of All Time .