Matt Groening’s recently announced Netflix series Disenchantment doesn’t sound like a whole lot of fun. Set in a ruined medieval city called Dreamland, it will follow the grubby adventures of an alcoholic princess, her elf companion and a demon. Groening himself has said: “Disenchantment will be about life and death, love and sex, and how to keep laughing in a world full of suffering and idiots, despite what the elders and wizards and other jerks tell you.”

For newcomers, or people who have only enjoyed a passing relationship with The Simpsons, this might seem off-puttingly grim. To animation geeks it might sound like Disenchantment is the result of Groening casting his eyes around the current cartoon climate and attempting to marry the emo absurdity of Adventure Time with the exhausted depression of BoJack Horseman.

However, if you think that Disenchantment will be uncharacteristically dark for a Matt Groening project, you probably haven’t been paying much attention to Matt Groening. Because yes, Groening created America’s longest-running sitcom, The Simpsons, and is therefore responsible for a juddering mountain of child-friendly cash-in merchandise, but the phenomenal success of that series has helped to obscure a fairly pronounced misanthropic streak.

Groening’s Life in Hell comic strip from 1994. Photograph: Life in Hell™ and © Matt Groening Productions, Inc. Courtesy of Acme Features Syndicate. All Rights Reserved.

The best insight into Groening’s tendency for gloom is probably Life in Hell, the bracingly black weekly comic strip he wrote between 1977 and 2012. The Simpsons might have made Groening his fortune, but it’s this that feels more like his life’s work.

Groening started writing Life in Hell at the age of 23 after moving to Los Angeles, and began to sell it for two dollars a pop in the Sunset Boulevard record shop he worked in. Loosely hung upon a one-eared rabbit called Binky, his estranged wife and their illegitimate son, the comic is undoubtedly the work of a young man in a rut, seething in a dead-end job in a too-hot town. Since arriving in the city he’d been a waiter, a dishwasher, a chauffeur, and this was his only way out. Even though he continued to produce Life in Hell while achieving all his dreams and becoming richer than he could ever imagine, its unceasing cynicism is a thing to behold.

If you scroll through the Life in Hell archive, stopping on random strips to read arbitrary panels, you’ll see what I mean. I guarantee that you will almost definitely land upon a snatch of dialogue that could have easily come from a particularly miserable Ingmar Bergman film: “You lied to me about God”, “Extreme pain”, “And the bombs destroy the roads and the bridges and the buildings” and “What does human flesh taste of?”

Why did he keep it going in the midst of such success? Spite. As he told Rolling Stone before the final strip was printed: “A TV producer sneered at the strip and said, ‘Why do you bother? Give it up.’ Because of that, I dug in my heels and kept it going two decades longer than I might have.”

Groening’s family … left to right, brother Mark, sister Lisa, mother Marge, sister Maggie, Matt and sister Lisa. Photograph: REX/Shutterstock

In fact, Life in Hell’s dysfunctional rabbits meant so much to Groening that he essentially invented The Simpsons to protect them. Invited, based on the strength of Binky and the gang, to pitch short form ideas for Fox’s The Tracey Ullman Show, he suffered a last-minute attack of nerves – what if they take my beloved characters away from me? – and instead drew a quick sketch of his family; his dad Homer, his mother Marge (maiden name: Wiggum), his siblings Mark and Patty and Maggie and Lisa. That sketch became The Simpsons. And it’s all thanks to a low-lying mistrust of authority.

Futurama, too, had an unmistakable bite to it. Not only did its cast include a deliberately grotesque lobster monster and an alcoholic, immoral robot who came loaded with the catchphrase “Kill all humans”, but it was set far in the future, during the logical end of capitalism.

In this world, all citizens are implanted with a “career chip” that assigns them one career for life. Advertising hoardings are so overwhelming that the opening credits end with a spaceship crashing into one, and death has been commoditised into nothing more than a lifestyle choice. Notable figures of the past stuck around long past their time as grotesquely withered cryogenic heads, while members of the public were encouraged to take advantage of the suicide booths on every street corner.

An unmistakable bite … the cast of Futurama. Photograph: Fox

Back when it debuted in 1999, reviewers were startled by its savagery. “Futurama ain’t The Simpsons,” declared Variety in an early review, perhaps forgetting that when The Simpsons started it was largely the tale of an obese layabout dad whose primary hobby involved strangling his son until the boy’s eyes bulged out of his head. So on reflection, Disenchantment – an adult fantasy about wizard sex that stars a woman with addiction issues and a literal demon – will slot comfortably into Matt Groening’s oeuvre, rather than representing an obtuse jag away from it.

Groening’s slightly jaundiced worldview has always been fed into the mincer along with those of his collaborators. In the case of The Simpsons, it was softened considerably by the presence of James L Brooks, a giant of film-making whose career has deftly balanced the satirical barbs of Broadcast News with the deep well of sincerity found in Terms of Endearment. It was this mix of attitudes and approaches that made The Simpsons so culturally beloved; a show that could be condemned in public by George Bush Sr while still enrapturing enough people to warrant 618 episodes, a movie and a theme park.

If you were to watch any of The Simpsons’ most tender moments – Maggie’s first word; the flashback episode that showed Homer and Marge getting together; You Are Lisa Simpson; the gorgeous ending to And Maggie Makes Three (where Homer uses photos of Maggie to deface Mr Burns’ “Don’t forget you’re here forever” sign until it reads “Do it for her”) – you’d probably see Brooks’s influence. But Futurama, which Groening ran with David X Cohen, was just as capable of disarming sweetness.

Although its lifespan came in fits and starts, the Futurama episode The Devil’s Hands Are Idle Playthings was originally intended to be the last. Fox had washed its hands of the show, and before huge DVD sales brought about a recommission, Futurama needed to find a way to wrap up a love-hate relationship between Fry, the lead character, and Leela, his one-eyed colleague. The way it went about doing this, by choosing to end on a childlike note of hopeful ambiguity, was sentimental in the extreme. Strings soared. Hands were held. Tears were shed. It was one of the most perfect television finales ever made, and it came from the same calloused heart responsible for Life in Hell.

So perhaps Matt Groening isn’t a complete monster. And perhaps, when a tender moment does break through all this despair, its effect is magnified. An entire series of “Do it for her” would be unwatchably nauseating. But thrown in at the end of a sour comedy about a hopeless man who’s forced to beg to return to a job he hates, it hits like a hammer.

This is Matt Groening’s real masterstroke. By mixing his love of humanity with his hatred for mankind, he’s helped to create some of the most legendary – not to say three-dimensional – cartoon characters the world has ever seen. And so it looks to be with Disenchantment. It sounds horrifically bleak. It will, at times, be horrifically bleak. But it’s a Matt Groening show, so it’s bound to have far more heart than you could ever expect. If he made it, it’s going to be tremendous.