The writer, who celebrates his 70th birthday November 9, got his start writing a script for Marvel’s Deadly Hands of Kung-Fu anthology in 1974 — a circumstance born of necessity, as the comic was behind deadline and needed an already-drawn story dialogued overnight; Mantlo, at the time a production assistant at the company, volunteered for the gig and impressed editors enough to be given the writing gig on an ongoing basis. In terms of breaks, it was both a blessing and a curse; the success of the script also meant that he became, in his own words, the “fill-in king” for Marvel over the next couple of years, required to supply last-minute scripts for everything from Iron Man and The Mighty Thor to Ghost Rider and Frankenstein in order to keep everything running on schedule, often with very little context to what else had been happening with the characters in question.

(Mantlo said in a 1979 fanzine interview that his script for Uncanny X-Men #96 — only the third issue of the “All-New All-Different” revival of the franchise that added characters like Nightcrawler, Colossus, Storm, and Wolverine to the team — had been unfairly criticized by fans for reasons outside of his control: “At the time my fill-in was scripted, only the very first appearance of the new X-Men had premiered, and none of Chris Claremont’s subsequent character development had been initiated. When mine did run, readers asked where all that characterization went. Had I been able to respond at the time, I would have said, ‘Hey! There weren’t none when I wrote my issue!’”)

Because of his seeming ease dropping in to handle any character’s adventures, Mantlo would go on to write almost every major (and less so) Marvel title over the next few years, scripting The Amazing Spider-Man, Fantastic Four, Champions, Howard the Duck, Captain America and multiple issues of both Marvel Team-Up and Marvel Two-in-One between the mid-70s and mid-80s, alongside more unexpected works, like adapting Treasure Island into comics or writing the entire run of The Human Fly, a short-lived series about a superhero based on real-life stuntman Rick Rojatt. While he was serving as, arguably, the most journeyman writer on the books at the self-proclaimed House of Ideas, Mantlo was also quietly creating three of the most interesting, and most unlikely, long term runs Marvel was publishing at the time.

The first of those runs was Micronauts, a book created at the express request of Mantlo himself. Based on a short-lived MEGO toy line that his son was playing with, Micronauts saw Mantlo transform what was a relatively generic sci-fi concept — robots and aliens, but they’re small! — into a ridiculously ambitious space opera clearly inspired (and shamelessly referencing) everything from Jack Kirby and Star Wars to classic pulp sci-fi, infused with more than a little religious and historical imagery. In fact, the toy line might have had less to do with the end result than Kirby’s Fourth World material, even in the series’ earliest days; the majority of the cast were original creations, with even those taken from the toys radically reinvented in the translation from toy to page.

Paired with artists including Michael Golden, Gil Kane, and Jackson Guice, Mantlo stayed on the series for 58 issues and two annuals across five years. Complicated rights issues — Hasbro owns the Micronauts properties, and Marvel owns the original characters — have ensured that the material has never been collected, but it remains some of the best “cosmic” material Marvel has ever published.

Running almost parallel to Micronauts was Rom, Spaceknight — another comic based on a short-lived toy line from the late ‘70s. Firmly set in the middle of the Marvel Universe, Rom was a riff on Invasion of the Body Snatchers with the volume turned all the way up; an alien race of shape-shifters called “the Dire Wraiths” had invaded Earth, disguised as regular humans, and only Rom could save us all thanks to the toyetic tech he utilized. Mantlo was accompanied by two veterans for the majority of the series — Sal Buscema and Steve Ditko — and what they created together was a wonderfully blunt, at times comedically lurid, take on what a horror/superhero/science-fiction hybrid would look like, filtered through the self-conscious post-Stan Lee identity politics of Marvel Comics at the time. This one lasted seven years and 75 issues, and again, so combines Marvel and Hasbro IP that it’s never managed to be reprinted fully.

The final of Mantlo’s three masterpieces is one that Marvel owns outright, yet somehow remains under-the-radar for reasons unclear. For six years — and just under seventy issues — Mantlo was the writer on The Incredible Hulk, one of the company’s flagship titles. Six years is a long time to write such a well-storied character, and initially it showed… until Mantlo got, it appeared, bored of the status quo and wanted to shake things up.

Within a couple of years, the traditionally stupid Hulk had the intelligence of his scientist alter ego, leading to a smart Hulk years before fan-favorite writer Peter David made the “grey Hulk” into a thing; arguably more importantly, a year-long sequence of fantasy stories in which a once-again mindless, savage Hulk was exiled into an inter-dimensional crossroads climaxed with “Monster,” a story in which Mantlo surprisingly deftly re-examined the early life of Bruce Banner, establishing both that his father had been physically abusive, and implying that Banner suffered from Dissociative Identity Disorder, two facts at the heart of the critically acclaimed, just-completed, Immortal Hulk comic book series.

It should probably be pointed out that Mantlo did something else in his Hulk run that resonated with audiences years after the fact; midway through Mantlo’s run, he took advantage of the opportunity to reintroduce and refine a one-off character he’s co-created at the very start of his writing career — one who would eventually become one of the breakout characters from 2014’s massively successful Guardians of the Galaxy movie. In retrospect, Rocket Raccoon bears the hallmarks of Mantlo’s writing, being at once derivative — he is, after all, named for a song from the Beatles’ White Album, with his initial appearance giving him the nickname “Rocky” to close that particular loop — and appealingly off-the-wall at the same time, and finding something worth exploring inside what could otherwise feel like a one-note joke.

“Monster,” which saw print in his penultimate Hulk issue, was, perhaps, Mantlo’s last great comic book story; by the mid-80s, he already had one foot out of the industry as he enrolled in law school, going on to all but leave comics behind to work as a public defender in the Bronx. (Work that appeared while he was working in law included scripts for the three issue DC series Invasion!, which was plotted by his Rocket Raccoon co-creator Keith Giffen; it’s appropriately pulpy and melodramatic in tone, even though that might not have been appreciated by the target audience at the time.) Tragically, in 1992, he was hit by a car and suffered severe head trauma, leaving him initially in a coma, and later in need of full-time healthcare as the result of cognitive deterioration as a result of the accident; his brother, Michael Mantlo, has been responsible for his well being for close to three decades at this point.

It’s simplistic to say that Mantlo suffered in terms of his reputation from lacking that a definitive comics project, as Watchmen and V For Vendetta had been to Alan Moore, or X-Men was for Chris Claremont; both Micronauts and Rom could make strong claims to being his magnum opus, although both are essentially lost to history due to their complicated rights situations. The material of Mantlo’s that readers have had the opportunity to enjoy for the last few decades through reprints, digital editions or inclusion in expensive hardcovers to tie in with some movie or another hasn’t been him at his best, as fun as it can be, and often is; the many fill-ins or truncated attempts to write mainstream superheroes on extended runs are, more often than not, Mantlo doing the job the best he can, in repeatedly rushed or complicated circumstances.

If there’s any justice, some publisher will make deals to make full reprint programs for both Rom Spaceknight and Micronauts possible, allowing contemporary audiences the chance to see Bill Mantlo at his pulpy, gloriously shameless, over-the-top best; in many ways, he shares a lot of traits with the writers working at the same time on the other side of the Atlantic as 2000 AD was in its infancy, and it could be argued that his best work reads far better today, in the self-aware, self-reflective 21st century, than when it was initially released. If others could be allowed to make birthday wishes on his behalf, here’s hoping that Mantlo’s reputation as the inventive, funny, will be thoroughly redeemed sooner, rather than later.