The Horrorist was an occult and horror-themed comic book limited series written by Jamie Delano, with art by David Lloyd, published by the DC Comics imprint Vertigo.
 It was a spin-off of Vertigo's popular "Hellblazer" series and features the character John Constantine.
 The book consisted of two 52-page issues without advertisements, published in December 1995 and January 1996 respectively.
Matt Ryan (born Matthew Darren Evans; 11 April 1981) is a Welsh actor from Swansea, best known as Edward Kenway in the Ubisoft video game "" and John Constantine in the NBC series "Constantine" and The CW series "Arrow", as well as voicing the character in the 2017 film "Justice League Dark".
Heartland is a comic book one-shot published by the Vertigo imprint of DC Comics in March 1997.
 It was written by Garth Ennis and illustrated by Steve Dillon.
 It is a spin-off from the "Hellblazer" comic book series, and features the character of Kit Ryan, a longtime supporting character in that series.
 Although "Heartland" is technically a spin-off of "Hellblazer", the central character of that series, John Constantine, makes no appearance.
Stephen R. "Steve" Bissette (born March 14, 1955) is an American comics artist, editor, and publisher with a focus on the horror genre.
 He is known for working with writer Alan Moore and inker John Totleben on the DC comic book "Swamp Thing" in the 1980s.
Constantine is an ongoing comic book series published by DC Comics, which started in March 2013.
 It features British exorcist John Constantine re-established into the DC Universe, and replaces the former Vertigo Comics title "Hellblazer", which ended with its 300th issue after 25 years, in February 2013.
 The title character was originally created by Alan Moore in his 1980s run on "Swamp Thing".
Constantine is a 2005 American occult detective film directed by Francis Lawrence (in his directorial debut) and starring Keanu Reeves as John Constantine.
 Rachel Weisz, Shia LaBeouf, Tilda Swinton, Pruitt Taylor Vince, and Djimon Hounsou co-star.
 With a screenplay by Kevin Brodbin and Frank Cappello, the film is based on DC Comics' "Hellblazer" comic book, with plot elements taken from the "Dangerous Habits" story arc (issues #4146) and the "Original Sins" story arc.
 The film portrays John Constantine as a cynic with the ability to perceive and communicate with half-angels and half-demons in their true form.
 He seeks salvation from eternal damnation in Hell for a suicide attempt in his youth.
 Constantine exorcises demons back to Hell to earn favor with Heaven but has become weary over time.
 With terminal lung cancer, he helps a troubled police detective learn the truth about her sister's death while simultaneously unraveling a much larger and darker plot.
Hellblazer (also known as John Constantine, Hellblazer) is an American contemporary horror comic book series, originally published by DC Comics, and subsequently by the Vertigo imprint since March 1993 when the imprint was introduced.
 Its central character is the streetwise magician John Constantine, who was created by Alan Moore and Stephen R. Bissette, and first appeared as a supporting character in "The Saga of the Swamp Thing" #37 (June 1985), during that creative team's run on that title.
 "Hellblazer" had been published continuously since January 1988, and was Vertigo's longest running title, the only remaining publication from the imprint's launch.
 In 2013, the series concluded with issue 300, and has been replaced by a DC Universe title, "Constantine".
 It was then relaunched in 2016 with the title "The Hellblazer" as part of "DC Universe Rebirth", restoring the character to his original cast, tone and setting.
 Well known for its political and social commentary, the series has spawned a film adaptation, television show, novels, and multiple spin-offs and crossovers.
John Constantine ( ) is a fictional antihero, appearing in comic books published by DC Comics and its alternative imprint Vertigo.
 The character first appeared in "Swamp Thing" Vol.
 2 No. 25 (June 1984), and was created by Alan Moore, Steve Bissette and John Totleben.
 He serves as the lead character of the comic books "Hellblazer" (1988–2013), "Constantine" (2013–15), "Constantine: The Hellblazer" (2015–16), and "The Hellblazer" (2016–).
Hellblazer Special: Bad Blood was a comic book limited series published by the Vertigo imprint of DC Comics in 2000.
 It was written by Jamie Delano and illustrated by Philip Bond, and features the character John Constantine, albeit several decades after most of his series continuity.
Constantine is an American television series developed by Daniel Cerone and David S. Goyer for NBC, featuring the DC Comics character John Constantine.
 Matt Ryan stars as Constantine, a British exorcist and occult detective who actively hunts supernatural entities.
 The series aired from October 24, 2014 to February 13, 2015, over 13 episodes.
 On May 8, 2015, NBC canceled "Constantine" after only one season due to poor ratings.
 Ryan reprised the role in a guest appearance in the fourth season of The CW series "Arrow", set within the Arrowverse, and it was announced in January 2017 that he would voice the character in an animated web series on The CW Seed later that year.

Question: The creator of character John Constantine, born in 1955, also worked on what comic? 
Answer: Swamp Thing