It’s hard to imagine the thought process that occurred inside the mind of the first person who watched Troma’s ludicrously gory, excessively grotesque 1984 schlockfest The Toxic Avenger and thought, “This would make a great kids’ cartoon.” And yet, in 1991, that’s exactly what happened. Amazingly, just like the low-budget gorefest that spawned it, Toxic Crusaders became a cult hit with a dedicated fanbase that has endured much longer than its 13-episode run.

To turn the story of a bullied teenager transformed by toxic waste into a deformed superhuman who battles evil with the aid of a sentient mop (as you do), the cartoon’s creators did what a lot of other ‘toons were doing in the early ‘90s: made it a treatise on the environment.

Yes, that’s right, when kids sat down to watch the considerably less violent adventures of Toxie and his team of malformed misfits taking on the villains from the planet Smogula, they were secretly being taught not to pollute the earth. ‘Smogula’. Now I get it! Learning is fun.

‘Conan the Adventurer’ (‘Conan the Destroyer’, 1984)

Translating Arnold Schwarzenegger’s brutal barbarian hero into a Saturday morning cartoon was a tall order. For one thing, the violence and sexuality inherent in Robert E Howard’s classic pulp warrior would need to be toned down. In a cartoon world, the rippling biceps of Conan couldn’t lop heads off and run swords straight through his enemies anymore; instead, they would need to be ‘banished’ or turned to stone. The ancient long-haired lothario certainly couldn’t have his way with as many maidens, either. On top of that, the title of the movie would also need to be rethought: Conan the Destroyer was a bit too extreme for kiddies, but Conan the Adventurer? That could go on lunchboxes.

Ultimately, Conan the Adventurer turned out to be one of the better bets of the era, running for two seasons and 65 episodes. It’s highly likely that most of the kids who watched it had never laid eyes on Schwarzenegger’s cult films, so to them, they were just watching a cartoon that scratched the same itch as He-Man and the Masters of the Universe.

Brilliantly, the theme song took the same tack as many others in the era: namely, it spelled out its title character’s bona fides in uber-dramatic fashion. Try these bars on for size: “Conan: The Adventurer / Conan warrior without fear / He’s more powerful than any man / whose legend ever crossed the land or sea.” Cartoon poetry.

‘Rambo: The Force of Freedom’ (‘First Blood’, 1982)

If there’s one thing I know about children, especially little boys, it’s that they love their heroes to be grief-stricken Vietnam War veterans, broken and brutalised by their experiences in the senseless conflict. I am, of course, kidding, because when toy company Coleco paid $15 million to turn Sylvester Stallone’s First Blood movies into an animated show, the first thing it did was jettison any hint at John Rambo’s crippling PTSD. Instead, they reenvisioned Rambo as the leader of a heroic military unit called The Force of Freedom, who battled the evil SAVAGE terrorist organisation every week.

To any fan of the ‘80s toy/cartoon behemoth GI Joe, that description will sound suspiciously familiar – and it should. The makers of Rambo: The Force of Freedom basically ripped off GI Joe wholesale, replacing COBRA with SAVAGE (which, of course, stood for Specialist Administrators of Vengeance, Anarchy, and Global Extortion), and ensuring each episode ended with a po-faced moral for children to chew on at school. Or, more likely, immediately forget forever.

Interestingly, Rambo: The Force of Freedom was the very first R-rated movie turned into a cartoon, and it did generate some column inches at the time. Unfortunately for the creators, though, one of the show’s chief detractors was Stallone himself, who also hated that a toy line had been produced based on characters intended for an adult audience. “It’s not for kids,” he grumbled to the Chicago Tribune. “The movie was not supposed to be for little kids, and I wouldn’t let my own children play with those toys.”

‘Beetlejuice’ (‘Beetlejuice’, 1988)

In Tim Burton’s Beetlejuice, Michael Keaton’s titular ‘Ghost with the Most’ is a disgusting, lecherous creep who lusts after every woman he sees and wants to marry a teenager to return to the land of the living. This isn’t exactly the sort of stuff you’d expect to see in a children’s cartoon. Thankfully, though, Keaton’s creation was also hilarious and tons of fun to watch, so he lent himself to animation much more than some other characters did. All the creators had to do was tone down the sex pest stuff and crank up the mischievous prankster meter!

In truth, Beetlejuice already had a leg up on most other R-rated cartoon conversions because key creative voices behind the film were involved. Burton, who once worked in animation at Disney, developed the show himself, and composer Danny Elfman also re-worked his film score to create the show’s theme song. Every week, Lydia Deetz, played by Winona Ryder in the movie, would travel into the ‘Neitherworld’ (changed from ‘Afterlife’ in case the concept of death scared the kiddies) and have adventures with her ghost pal, Beetlejuice.

Surprisingly, this formula actually produced enough laughs and clever scenarios for the show to run for a very healthy four seasons and 96 episodes. Indeed, the Beetlejuice animated series is still fondly thought of by fans, and the spin-off toys still do great business on eBay and at conventions. It just goes to show that sometimes, against all the odds, a wildly inappropriate movie can make a darn good Saturday morning cartoon.

‘Operation: Aliens’ (‘Aliens’, 1986)

Technically, this entry is a bit of a cheat, as no Operation: Aliens cartoon ever saw the light of day. Still, a toy line associated with the prospective animated series was released in stores, as was a board game, before it was decided that work on the series itself would be scrapped.

In the early ‘90s, while David Fincher’s ill-fated Alien 3 was in development, 20th Century Fox and Kenner teamed up to make toys and a cartoon based on James Cameron’s classic 1986 sci-fi/horror shoot ‘em up, Aliens. The series would have followed Ripley, Hicks, and a team of buffed-up space marines as they blasted the xenomorphs across the galaxy, leaning heavily into the action side of things, as opposed to rib-bursting horror.

A Korean animation studio put together the pilot episode, titled Operation: Aliens. Then, in the summer of ‘92, the show was unexpectedly cancelled, and the pilot has never been seen. Hell, it’s never even leaked online. All that is left of it are a handful of screenshots and some artwork showcasing the animation style and title logo design.

It’s not known exactly why Fox pulled the plug, but it’s likely because the executives watched the pilot and realised there was no way HR Giger’s horrifying xenomorph wouldn’t give children nightmares, even in cartoon form. Whatever the case, a handful of gooey, monstrous toys did make it to market, and probably inspired just as many bad dreams as any cartoon could have.

‘Highlander: The Animated Series’ (‘Highlander’, 1986)

In the ‘90s, relocating characters previously associated with the modern-day into the future was all the rage, as Batman Beyond and Spider-Man 2099 can attest to. In ‘94, though, this treatment was given to the Highlander film franchise, and a cartoon was commissioned that followed Quentin, a descendant of Christopher Lambert’s Connor MacLeod, in the 27th century. He is trained by Don Vincente Marino Ramírez, an immortal who bears an uncanny resemblance to Sean Connery’s Juan Sánchez-Villalobos Ramírez from the film series, but isn’t the same character. For some reason. Don’t ask me why.

However, despite the Highlander series having one of the most complicated mythologies around, and its central conceit being structured around immortal dudes trying to behead each other, it worked remarkably well as a cartoon. This was the mid-’90s, so the show could push boundaries a little more than its ‘80s counterparts, meaning it allowed characters to perish, told nuanced stories with morally grey characters, and even included the occasional decapitation. You know, for the kids!

At the end of the day, Highlander: The Animated Series‘ 40 episodes were, by most accounts, much better than they had any right to be, so if you really want to watch a cartoon spinoff of a wildly inappropriate movie…there can be only one (sorry).

‘RoboCop’ (‘RoboCop’, 1987)

In the late ’80s, Marvel owned the rights to make comics and cartoons based on Paul Verhoeven’s insanely violent, wickedly satirical RoboCop. Was the story of a near-future police officer gunned down in the line of duty in vomit-inducing fashion, before being turned into an unfeeling cyborg cop ideal for a kids’ cartoon? No, of course not. But RoboCop looked cool as shit, so the fact that the movie wasn’t suitable for children was the last thing on anyone’s mind. There was money to be made!

The series ended up hitting the airwaves a year after Verhoeven’s movie, sanitising all the violence and anti-corporate, anti-policing satirical elements. Unfortunately, RoboCop’s cool design could only go so far, and it wasn’t able to make up for Marvel pulling the spine out of the character’s story. It wasn’t surprising to anyone involved when the show only lasted 12 episodes.

Fascinatingly, though, Marvel Productions actually chose to use the budget for a prospective final 13th episode to make an X-Men pilot instead. Unfortunately, this was several years before the comics giant would hit paydirt with X-Men: The Animated Series, and the pilot produced here – Pryde of the X-Men – wasn’t picked up to series. Instead, it spawned three separate video games, despite no cartoon being on the air. The ‘90s were a weird time.

‘Roughnecks: Starship Troopers Chronicles’ (‘Starship Troopers’, 1997)

A decade after one Paul Verhoeven satirical sci-fi classic had all its edges filed off to become a children’s cartoon, another followed suit. Roughnecks: Starship Troopers Chronicles was a 3D computer-animated spinoff of Verhoeven’s ‘97 bug attack classic, which famously tackled subjects like colonialism, authoritarianism, and xenophobia within the context of a sci-fi action movie filled with giant bugs being blasted by big ol’ space lasers.

Verhoeven hated fascism, thanks to a childhood spent growing up next to a German military base in World War II-era Holland, and he saw Starship Troopers as a way to sneak political commentary into a popcorn movie. Naturally, though, none of this was likely to make it into a children’s cartoon, so Roughnecks wound up a much more straightforward ‘bughunt’ show.

To give credit where it’s due, despite stripping the source material of its weighty themes, Roughnecks was good enough that it developed a pretty passionate fanbase who were furious when it was cancelled after 40 episodes. Ultimately, it was aimed at a slightly older audience than the ‘toons of the ‘80s, and that young teenage crowd ate it up, before gleefully buying the DVD boxsets in the hopes of getting more episodes greenlit. Those poor fools.

‘Swamp Thing’ (‘Swamp Thing’, 1982)

As a kid, I remember watching the Swamp Thing cartoon, based on the infamous DC Comics character, and loving it. Or, to be more accurate, I remember watching the opening theme of Swamp Thing, which featured a hilariously on-the-nose interpretation of The Troggs’ ‘Wild Thing’, complete with lyrics so cheesy they would have made Stan Lee blush: “Swamp Thing, you are amazing / You fight everything nasty / Swamp Thing / Earth really needs you!”

In the source comics, despite his silly moniker, Swamp Thing has always been a tragic horror character, whose stories are literary in their pretensions. His tales are artsier than most mainstream comics, and have thus attracted some of the greatest creators in the business. In other media, though, the big green monster has been decidedly less successful. There was the 1982 Wes Craven movie, which was more campy than terrifying, and it was followed by a 1989 sequel, which should remain nameless.

Then, the cartoon came along in 1991, and cast Swamp Thing and his mutant pals as goofy eco-adventurers, much like other ‘toons of the day like Captain Planet and the Planeteers. Astonishingly, the awesome theme song wasn’t enough to make the show stick around longer than five episodes, although there was a silver lining to the whole debacle. The accompanying toy line sold extremely well, showing that while the source material might be inappropriate for kids, in toy form, they’ll always love playing with repulsive, misshapen monsters.

‘Attack of the Killer Tomatoes’ (‘Return of the Killer Tomatoes’, 1988)

When the animation brains at Fox Kids began thinking about what movie they could turn into a Saturday morning cartoon next, I’d love to know how long it took them to arrive at Attack of the Killer Tomatoes. This B-movie spoof was released in 1978, and its grimy, dingy tale of sentient murderous tomatoes wasn’t particularly well-received. In ’88, though, it received a long-delayed sequel, which happened to star a very young George Clooney, and suddenly, a cult-classic franchise was in the making.

After the unexpected success of that sequel, entitled Return of the Killer Tomatoes, it was decided that children needed to get their own version of the gleefully demented series. Attack of the Killer Tomatoes included elements from both films, and managed to create something that landed squarely in the gross-out zone that young boys loved so much in that era.

Amazingly, the show ran for 21 episodes and retained a lot of the movies’ zany sense of humour. Sure, the jokes were less adult-oriented now, but they were still pretty funny. After all, if you can’t laugh at giant tomatoes with faces and sharp teeth trying to eat people, what can you laugh at?