In the early 1980s, a series of cartoons that were used to promote toy lines became blockbusters, with G.I. Joe: A Real American Hero, He-Man and the Masters of the Universe and The Transformers turning their hit TV series into gigantic promotions for toy lines, leading to multi-million dollar franchises. Those concepts, though, were toy lines where a cartoon was then invented to sell the toy. After the success of those shows, however, people began to try to create franchises that could work for both.

One of these ideas was ThunderCats, which debuted as an animated series before a toy line was released to tie in with the series. It was a major hit, one of the most successful animated series of the 1980s. It ran for four seasons between 1985-1989. Decades later, in 2011, a revival aired on Cartoon Network that lasted for one season (ostensibly split into two 13-episode mini-seasons). Like most cartoons, there were occasionally moments that were a bit inappropriate for kids. We'll detail 15 examples (from both series) as well as an infamous "gag reel" that went way over the line!

16 UNSETTLING, EVEN FOR MUMM-RA

The main villain on the ThunderCats was Mumm-Ra, who was always trying to get his grubby little mummified hands on the ThunderCats, because they were the only people on Third Earth that could challenge him for control of the planet. Despite the fact that he was quite powerful, he often chose to go with subterfuge to mess with the ThunderCats rather than brute force.

He would typically do so by changing his form and impersonating different creatures (he once even impersonated Snarf, Lion-O's trusty sidekick). However, by far the most disturbing transformation was when he became the adorable little fairy known as Dragonfly. Kids must have been freaked out as all heck when they heard Mumm-Ra's voice from this cute little creature! The transformation sequence was also quite trippy.

15 THE MUTANTS APPEAR TO BE OVER-COMPENSATING

The key thing about cartoon series that are tied into toy lines is that you not only have to introduce enough characters to make sure there were enough figures in it, but you also have to come up with ideas for vehicles for the toy line to sell. This was what led to some of the nonsense on the Super Powers toy line. That cartoon series didn't really have enough vehicles, so the toy line notoriously had to make up things like the Justice Jogger, which, as the name implies, helped Superman jog... presumably for "justice."

ThunderCats had plenty of vehicles to work with, but some of their names were more than a little bit suggestive. The evil mutants, for instance, rolled around in a machine called the Fist Pounder. That sounds like the sort of thing that you would buy from a store where you would have to wrap it in plain brown paper before leaving. One thing it does not sound like is a toy for kids!

14 MEXICAN FOOD... IN SPAAAAAACE!

The longer the ThunderCats remained on-air, the less logic the show employed. Essentially, the show's writers seemed to stop caring if things necessary made sense. That led to the opening of the late Season 2 episode, "Side Swipe," which is so bizarre that we can't imagine what little kids were thinking when they watched it.

It opens with Snarfer (Snarf's Scrappy Doo-esque nephew) headed off to pick up... Mexican take-out food?!? Yes, even though they're on some alien planet, Snarfer can fly off and bring back Mexican food. Then a villain freezes the neck of a heroic friend of the ThunderCats and Snarfer saves the day by pouring some hot sauces from the Mexican food into her mouth to cure her frozen throat. Yes, someone came up with this idea and it made it onto television.

13 HE SHOULD DOUBLE DATE WITH LICKITUNG

As noted, since the ThunderCats was a cartoon series first and a toy line second, when the toys blew up in popularity, there was a high demand for them, but not necessarily a whole lot of options within the TV series of things to turn into new figures or vehicles. That is how we got a toy based on the Tongue-a-Saurus, which is the most suggestive toy name this side of Lickitung.

The Tongue-a-Saurus only made one brief appearance on the TV series, but that was enough to be turned into not only a toy, but a rather large one! The Tongue-a-Saurus lives in the River of Despair. No wonder they call it the River of Despair if things like that are just laying around waiting to unfurl their tongues on you! Gross!

12 PAGING DR. FREUD...

On the original ThunderCats series, Tygra tended to be the ThunderCat who got the worst of it. Whenever something messed up happened, he was often the one it happened to. This was clear in the episode "Trouble With Time," where Tygra entered into a rather... suggestive looking cave and instantly had the life sucked out of him, as he rapidly aged into an old man.

In the end, the ThunderCats were able to save him by sending Cheetara into the strange-looking cave and she was somehow immune to its effects. So, a uniquely-shaped cave that sucks the life out of men? It seems like the Freudian aspects of the ThunderCats were running hog wild in this particular episode!

11 A CHAIN OF FOOLS

As noted earlier, the longer that the ThunderCats series lasted, the less sense the episodes made. Another great example of this was the Season 3 episode, "Chain of Loyalty," where we learn of a special magical chain that, when destroyed, not only broke the loyalty of the ThunderCats, but actually made them actively try to kill one another!

Lion-O had to beat them all up and tie them up before re-assembling the chain to get everyone back to their normal selves. It sure was a great message to send to the little kids watching that the ThunderCats were only friends with each other because of some magic necklace and that same delicate trinket was the only thing keeping them from actively trying to kill each other.

10 TO KILL A BUNCH OF BIRDS

In the original ThunderCats TV series, there was an evil character named Monkian, who was one of Mumm-Ra's generals. When the ThunderCats rebooted in 2011, his name was changed to Addicus (which is strange, since it sounds like Atticus Finch, the famed heroic lawyer from To Kill a Mockingbird). His introduction to the series was chilling.

He was about to be killed by a group of bird people for his crimes against them. He asked for a last meal and they told him no, since his last meal request was to eat one of them! So they cut him loose and let him fall to his death, but he was saved by Mumm-Ra's men. He then says that he has to settle up first with the meal he was promised, and leaps. The show then cut away to the sound of birds screaming. It was super disturbing.

9 TYGRA GETS LOOSE

In the 2011 ThunderCats series, Tygra's bad luck continued, as he was exposed to a love potion created by the mysterious Ponzi (as one of his schemes -- wink wink, nudge nudge) and it... well, it basically just made Tygra super-effeminate. It was a rather confusing concept for how a love potion should work. In the 2011 series, Tygra was a bit of a wise guy, but with the love potion, he was just goofy.

He called Panthro a "Silly goose" at one point. Amusingly, Ponzi accidentally had a potion that worked well (it could defeat Mumm-Ra). However, when the ThunderCats chased after him to get access to it, he assumed they were chasing him because they were mad that he ripped them off with one of his lame potions, like his "silly goose"-ifying love potion!

8 PEEPSHOW FOR MUTANTS

"The Circus Train" introduced an unscrupulous bounty hunter named Captain Bragg (why yes, this was a late-in-the-series episode, how could you guess?). Bragg was sent to Third Earth to get rid of the bad guys on the planet. How he chose to get rid of them was super disturbing.

He created a circus train and adopted the persona of a circus barker and tricked two of the Mutants into coming on to the train by promising them a female mutant peep show. He described the show in rather distinct detail, describing her as “gorgeous, glamorous, glittering” and “the object of your heart’s desire.” Captain Bragg is super weird. He also tricked WilyKat into helping him and had him dress up like a clown. So that happened.

7 TYGRA TRIPS HARD

As we have seen, things often don't go right for Tygra on the series, but never has this been more evident than in the episode "Garden of Delights." In the episode, Mumm-Ra takes on the form of a talking plant and tricks Tygra into eating a delicious (but hypnotic) plant. The plant then causes Tygra to hallucinate. It was extremely disturbing for little kids to see a guy flat out trip balls like this.

Not only that, but the show showed how much drugs can ruin your life when an addicted Tygra agrees to betray the rest of the team so long as he can get his hands on more of that good, good skag. If it weren't so messed up, this would be a bold choice to show the realities of substance abuse.

6 SHE'S NOT JUST A CHEETAH, SHE'S ALSO A COUGAR

One of the things that the 2011 series changed from the original is that Lion-O is now a teenager. That's a significant plot point, because it led to one of the most confusing/inappropriate aspects of the original series. You see, when the show debuted, Lion-O was a kid, not much older than WilyKat or WilyKit and it is just when he gets the Sword of Omens that he is transformed into an adult body.

However, he's still a kid, so it was very inappropriate the way that there was always a great deal of sexual tension between Cheetara, an adult, and Lion-O, a kid trapped in an adult's body. Remember how disturbing Big was in retrospect when you think of the things that Elizabeth Perkins did with "big" Josh? Well, every episode of ThunderCats had the tension of that happening.

5 DON'T STEP ON HIS SAMOFLANGE!

The 2011 ThunderCats series was remarkable in just how much the show was clearly devoted to the fans of the original series. It updated things, but in general, it kept them mostly the same; moreover, they clearly knew the past of the show very well. One of the areas where creators showed their love of the old show was in Easter Eggs and other little references to the old show.

One of the dirtiest Easter Eggs was when Panthro is working on a tank when Tygra comes by to talk to him and steps on his samoflange. Everyone, of course, is curious as to what a samoflange is, exactly. Hilariously, it is a reference to an old outtake from the show where the actors break up and beginning cursing when they can't figure out what the heck a samoflange is, either.

4 RING MY BELL

Another notable change in the 2011 series was that Tygra is now the adopted older brother of Lion-O, so the two have had a sibling rivalry that has lasted since they were little kids. Tygra often gives his little brother a hard time. The truly bizarre thing, however, is that all of his teasing of Lion-O honestly often comes off as, well, flirting.

There is one moment early in the first episode where they are competing to see who can ring a bell at the top of a big tree first. Lion-O says, "I'm going to ring that bell." Tygra winks and says, "I'll ring your bell." Dude, that doesn't even make sense! It led to a whole meme with people using that non-sensical (yet sensual) taunt.

3 GETTING HIS SWORD UP

Since Lion-O was older on the 2011 series, it was therefore okay that he and Cheetara flirt with each other, and flirt they certainly did! The whole time that the ThunderCats have been in existence, there has been a certain phallic aspect of the Sword of Omens, how it is a sword that starts out tiny and then elongates in times of need.

That aspect of the sword was definitely being referenced in one episode of the 2011 series where Lion-O can't get the sword to show him where to go and Cheetara comes up behind him and whispers in his ear to encourage him to use the sword. The show even calls attention to the sexual nature of her whispers when WilyKat and WilyKit happen upon them and they say, "We know what you were doing!"

2 SOME NUDITY REQUIRED

Truly the most bizarre aspect of the ThunderCats series is that in the very first episode, before they land at their new home of Third Earth (where they somehow turn their spaceship into an expansive headquarters after landing, but that's neither here nor there), they are all sans-clothes, resplendent in their birthday suits!

Not only are they nekkid, but they still are wearing their belts. So, apparently, space travel requires you to not wear any clothing... except belts? It is the most bonkers thing imaginable. It also likely led to some confused feelings for certain viewers while watching an unclothed Cheetara. The implication is that they naturally don't wear any clothes, but will only wear clothes on Third Earth for protection's sake, but it is still super wild.

1 GOING TOO FAR: THE THUNDERCATS GO WILD!

Wildest of all is the infamous ThunderCats blooper reel. You see, when voice actors show up to record their lines, they often will screw up. We, naturally, never get to hear most of these screw-ups, because cartoons don't usually have blooper reels. However, one heroic sound engineer (or some other employee) got enough of a kick out of the ThunderCats outtakes that they kept a recording of them and eventually it leaked on to the internet.

Hearing the great Earle Hyman (Panthro's voice actor and Cliff Huxtable's dad on The Cosby Show, who just died in November of 2017 at age 91) swear over one of his lines is hilarious. Hearing Lion-O curse out Snarf is also glorious. Be sure to go look on the internet for the ThunderCats outtakes!