Nothing can sum up Keith Giffen’s character better than the Facebook post he wrote to announce his own death at the age of 70: “I told them I was sick … Anything not to go to New York Comic Con. Thanx. Keith Giffen 1952-2023. Bwah ha ha ha ha.”

That eruption of maniacal merriment was recognised by comic fans as a last defiant laugh from the sardonic comic writer and artist, who has died of complications following a stroke, after a 50-year career during which he created many memorable characters including Jaime Reyes (Blue Beetle), Rocket Raccoon, Ambush Bug and Lobo.

A Mexican-American teenager, Reyes first appeared in Infinite Crisis #3 (2006) and became Blue Beetle two issues later, when he gained superhuman powers via a scarab that morphs into an alien battle suit, eventually going on to appear in the 2023 Blue Beetle movie.

One of the stars of the Guardians of the Galaxy movies was created by Giffen early in his artistic career. Rocket Raccoon was a smart-mouthed anthropomorphic weapons expert who first appeared in Marvel Preview #7 (1976), written by Bill Mantlo, who resurrected the character in his own four-part miniseries in 1985.

Among Giffen’s other early creations, Ambush Bug’s debut in DC Comics Presents #52 (1982) and its sequel, which involved the Legion of Substitute Heroes, were so successful that they led to several miniseries and one-shots drawn by Giffen featuring the absurd, fancifully dressed alien wannabe hero, and a one-shot Legion of Substitute Heroes Special (1985).

In 1982 Giffen joined the writer Paul Levitz on The Legion of Super-Heroes #287 and began transforming the series into a saga of considerable depth. One of the most popular storylines in comic book history, The Great Darkness Saga (#290-294, 1982), featured Darkseid as its cosmic villain and Legionnaires and other heroes from across time teaming up to confront him. As a result, Legion of Super-Heroes became one of DC’s bestsellers of the early 1980s.

Lobo, who first appeared in Omega Men #3 (1983), was intended as a parody of violent characters such as Wolverine, but became a poster boy for violence when Giffen teamed up with the writer Alan Grant and artist Simon Bisley for Lobo: The Last Czarnian (1990), which spawned numerous miniseries and specials in which Giffen continually pushed the envelope of acceptability as Lobo battled everyone from Santa Claus to his own children. Combat Christ and the Howlin’ Apostles proved to be DC’s limit.

Giffen was heavily involved in numerous crossover event series, designed, he said, to “significantly alter the status quo or introduce new characters into the status quo”, including Invasion! (1988), the weekly 52 (2006-07) and Countdown to Final Crisis (2007-08) for DC, and Annihilation (2006-07) from Marvel. His creativity and tongue-in-cheek humour earned him a loyal fanbase and he won an Inkpot award in 1991.

The son of Rosa Ann (nee Duncan) and James, a salesman for a textile company, Giffen was born in Queens, New York, but grew up in Little Falls, New Jersey. He was a fan of comics from the age of eight, when his mother handed him a copy of World’s Finest, and especially loved Marvel’s monster books and Gene Colan’s Giant-Man. He began creating his own characters at high school and went on to spend “one abysmal year” at the School of Visual Arts in New York (“the less said about that, the better”).

Apart from a year of night classes at duCret School of Art, New Jersey, Giffen was self-taught, studying books on anatomy and perspective during his four years working as a hazardous materials handler at Hoffmann-La Roche pharmaceuticals. During a week’s holiday he decided to submit samples to comic companies. At Marvel, an artist had dropped out of illustrating a back-up story (The Sword and the Star) for Marvel Preview, and Mantlo, who had spotted Giffen’s portfolio, suggested they give him a try.

Giffen briefly produced layouts for Wally Wood on Justice Society of America for DC’s All Star Comics (1976), but was let go. After a period of selling vacuum cleaners door-to-door and other odd jobs, he tried again, drawing horror stories and Doctor Fate as a back-up strip in The Flash (1982), and working his way up to the Legion of Super-Heroes.

An accusation of “swiping” the work of José Muñoz in Ambush Bug (1985) – Giffen said he “parroted” it, rather than doing an outright copy – derailed his career for a time, until he was offered the chance to plot, and do breakdowns for, Justice League (1987-92) and its spinoff, Justice League Europe (1989-92), working with JM DeMatteis and Kevin Maguire. He also plotted and did breakdowns for Aquaman (1989) and plots for L.E.G.I.O.N. ’89/’90 (1989-90), a superhero group spun off from Invasion.

The range of Giffen’s output over the next 30 years was astonishing. He drew the superhero parodies The Heckler (1992-93) and Punx (1995-96), the return of Justice League International in Justice League: Generation Lost (2010), and episodes of Outsiders (2011), O.M.A.C. (2011-12) and Infinity Man and the Forever People (2014-15). He plotted or wrote full scripts for Eclipso (1992-93), Vext (1999), Suicide Squad (2001-02), a biography of HP Lovecraft (2004), Blue Beetle (2006-07), Midnighter (2007-08), Wetworks (2007-08), Reign in Hell (2008-09), Doom Patrol (2009-11), Booster Gold (2009-11), Magog (2009-10), Justice League 3000 (2014-15) and The New 52: Futures End (2014-15), all for DC; and for Marvel he wrote stories featuring Marvel Monsters: Where Monsters Dwell (2005), Drax the Destroyer (2005-06), Defenders (2005-06), Nick Fury’s Howling Commandos (2005-06) and Annihilation spin-offs Annihilation: Silver Surfer (2006) and Annihilation: Conquest – Starlord (2007).

During the same period he also penned or plotted various comics for Image (1993-94) and Valiant (1994-96), adaptations of Japanese manga, Battle Royale (2003-06) and Battle Vixens (2004-10), for Tokyopop and 10 (2005), Hero Squared (2005-07), Planetary Brigade (2006-07) and others for BOOM! Studios. He was also a storyboard artist for the animated shows Batman Beyond and Static Shock, as well as writing episodes of Ed, Edd n Eddy and Hi Hi Puffy AmiYumi for Cartoon Network.

In early 2023 he produced a podcast titled I’m Not Dead Yet, and had recently moved to Tampa in Florida.

He is survived by his children, Kyle and Melinda. His wife, Anna, predeceased him.

• Keith Ian Giffen, artist and writer, born 30 November 1952; died 9 October 2023