Waking up on a Saturday morning and enjoying your favorite cartoons with a bowl of cereal is one of the best things about being a kid. During those much simpler times, pretty much all we had to preoccupy our young minds with was cartoons and video games. As opposed to now, when we also need to engage in deep thought about complex TV show plots and multiple comic book timelines and universes. However, not all cartoons we used to watch as kids were in fact all that innocent. If you grew up in the '90s, chances are animated series such as Spider-Man, X-Men and TMNT were part of your everyday life.

RELATED: The 15 Most Offensive Superhero Cartoons (That You Still Love)

After re-watching our beloved childhood cartoons, we've come to some rather alarming findings. Whether it's off-color humor or social commentary, a number of these cartoons delved into pretty dark territories. Back in the day, when censorship was looser, a lot of questionable content seeped into kid’s cartoons. And while we may remember them dearly, it is quite possible that these cartoons may have scarred us for life. All aboard the Nostalgia Express, for today we take a look at 15 dark cartoons from our childhood that our parents should’ve never let us watch.

15 THE SIMPSONS

The Simpsons

The Simpsons certainly need no introduction. With 29 seasons, 619 episodes, The Simpsons is the longest-running American sitcom and longest-running American animated series. It revolves around the everyday working-class life of the Simpson family, which consists of Homer, Marge, Bart, Lisa and Maggie. The series is filled with satirical social commentary, as well as parody of the American culture, society, television and the human condition.

Although The Simpsons is both marketed and intended for mature audiences, kids all over the world grew up watching the mischievous Bart get into all sorts of trouble. The lack of punishment or consequences for Bart’s misbehavior led some parents to criticize the show for being a bad influence on children. And while we are thrilled that we got to watch this cartoon at such a young age, we can kind of see where these concerned parents are coming from.

14 X-MEN: THE ANIMATED SERIES

X-Men The Animated Series

X-Men: The Animated Series is responsible for turning a lot of '90s kids into nerds. The beloved and fondly remembered animated series debuted on Fox Network back in October of 1992 and lasted for five seasons. The series featured the characters from Jim Lee’s '90s X-Men line-up and adapted popular comic book storylines, such as the "Dark Phoenix Saga" and the "Days of Future Past."

Similarly, the cartoon also incorporated a great number of serious social issues that are present in the comics. X-Men: The Animated Series dealt with important topics including divorce, the Holocaust and even the AIDS hysteria. As expected, certain episodes turned out to be rather dark and not what you would call kids-friendly. Nevertheless, we tuned in every Saturday morning with our parents none the wiser.

13 EARTHWORM JIM

Earthworm Jim

Earthworm Jim is an animated series based on the video game of the same name, which ran for two seasons on Kids’ WB. The series centers around the escapades of an earthworm named Jim who becomes a superhero with a robotic super suit. Each episode featured a villain attempting to steal the suit, rule or destroy the universe, or cause mayhem in the galaxy.

The episodes always ended with a character being crushed by a cow, which is reminiscent of the video game where in the first stage the player launches a cow into the sky, only to have it crush the princess in the end. Earthworm Jim also tussled some rather serious topics, albeit in a ridiculous manner, such as changing careers and attending therapy. Plus, one episode features an evil Santa depicted as the Norse God of Judgment.

12 GARGOYLES

Gargoyles

Yet another forgotten gem from the 1990s, Gargoyles, is an animated series about a species of nocturnal creatures known as gargoyles that turn to stone during the day. After thousands of years spent in a petrified state, the gargoyles are reawakened in modern-day New York and take it upon themselves to defend the city.

The cartoon was fairly dark in tone with complex story arcs and lots of melodrama. Gargoyles frequently relied on references to Scottish history and Shakespeare in order to tell engaging and layered stories. Gargoyles didn’t shy away from mature content, serious matters and complex plotlines. Producer Greg Wiseman managed to blend the works of Shakespeare, the Arthurian legend and Celtic history all into once concept mix and somehow make it work.

11 SOUTH PARK

South Park

OK, no kid was supposed to watch South Park, but let’s be honest we all did watch it. This adult animated sitcom was the forbidden fruit all of us ever so lavishly consumed. South Park revolves around the bizarre adventures of a group of boys usually accompanied by an ensemble of recurring characters. The show is defined by its use of profanity, surreal and dark humor, as well as satire on a range of popular topics.

Aimed at mature audiences, South Park doesn’t hold back. Over the course of 21 seasons, thus far, this adult cartoon has addressed every possible social and political issue, parodied just about every celebrity ever and satirized our society in every conceivable way. Granted, we weren’t even able to understand much of it as kids, but hey it had cuss words, so we had to watch it.

10 ED, EDD N EDDY

Ed, Edd n Eddy

Ed, Edd n Eddy was a popular animated series that revolved around the three Eds, Ed, Edd (Double D) and Eddy. The boys would often come up with schemes to scam other kids out of money in order to buy their jawbreakers. However, their elaborate plans usually ended up in failure and humiliation for the Eds.

The cartoon reveled in the type of frenetic and often rather gross humor that appealed to kids, with a decent amount of bizarre insanity and adult jokes. Episode "The Day the Ed Stood Still" is particularly dark as it revolves around Ed becoming a monster, hunting down the kids of cul-de-sac and trapping them in his cereal-plastered lair. Ed, Edd n Eddy was indeed a kid’s cartoon, but that didn’t stop it from going pretty dark and incorporating adult humor and themes.

9 ROCKO’S MODERN LIFE

The main cast of Rocko's Modern Life

Rocko’s Modern Life is an animated sitcom that ran from 1993 to 1996 on Nickelodeon. The series is focused on the daily struggles of the titular anthropomorphic Australian-immigrant wallaby, his faithful dog Spunky and his cow friend Heffer. The series sparked a lot of controversy due to its common use of double entendre, innuendos and satirical social commentary.

In one especially dark episode, Heffer chokes on a chicken bone and dies. His soul starts to float to heaven but his wings soon turn into anvils and Heffer plummets down to hell. Heffer is then informed by a demon that he has been sent to hell because he committed the deadly sin of gluttony. And even though he was mortified by what he saw in hell, once resurrected Heffer still wants to get more food, proving that he effectively learned nothing. What a valuable lesson for young minds.

8 COW AND CHICKEN

A promotional still for the Cartoon Network show, Cow and Chicken

Cow and Chicken is an animated comedy series which ran on Cartoon Network during the late '90s. The series follows the surreal misadventures of two unlikely animal siblings, Cow and Chicken. Yes, those are their real names. But it gets even weirder, because they’re parents are human. The good-natured and dimwitted Cow and her cynical older brother Chicken are often involved in silly antics with their sworn enemy Red Guy, who uses various disguises to scam the sibling duo.

The series humor has been described as grotesque, repulsive and off-color. Much of the humor and storylines are based on traditional childhood worries, anxieties and phobias but heavily caricaturized. Cow and Chicken wasn't a stranger to sarcasm either, as the siblings would often order meals such as pork butts and taters.

7 BEAVIS AND BUTT-HEAD

Beavis and Butt-Head

Not so long ago, there was an animated series centered around two socially awkward teenage miscreants, Beavis and Butt-Head. Without any apparent adult supervision, these dimwitted and uneducated heavy metal fanboys would spend hours in front of the TV judging music videos. Without ever showing empathy or morals, Beavis and Butt-Head would usually judge anything related to sex, violence and the macabre as "cool."

Their immaturity and lack of social aptitude is further emphasized by their tendency to giggle on any use of innuendos and double entendre. The show relied heavily on a combination of lewd humor and implied criticism of society, for which it was both praised and chastised. In particular, the boys' obsession with fire and dangerous behavior caused controversies after parents started blaming Beavis and Butt-Head for their children’s mischievousness.

6 BATMAN: THE ANIMATED SERIES

Batman The Animated Series

The 1992 animated series based on the adventures of the Dark Knight still stands as one of the best cartoons out there. The critically acclaimed Batman: The Animated Series was praised for its dark tone, complex themes and artistic quality. The series is most notable for being adult-oriented, depicting physical violence, realistic firearms, and campy villains such as Clayface and Mr. Freeze. Plus, this series is responsible for the invention of Joker’s assistant, Harley Quinn.

In Harley's introductory episode, Joker throws Harley out the window and quite brutally lets her fall down several flights of stairs, which results in Harley being critically injured. But instead of, at the very least, getting mad at the Joker, Harley blames herself. Thus, the two get permanently locked in a horrifying cycle of abuse. Batman: The Animated Series certainly didn’t shy away from depicting even the darkest characters and moments from Batman comics.

5 PINKY AND THE BRAIN

Pinky and the Brain

Pinky and the Brain revolves around two genetically enhanced laboratory mice residing in a cage in the Acme Labs research facility. Every episode features the self-centered and scheming Brain devising a new plan to take over the world, which inevitably fails, more often than not due to something stupid Pinky does. Pinky and the Brain episodes were usually a parody of a movie or a novel.

In one of his best attempts to take over the world, Brain bought every property in the world above the 39th floor, plotting to melt the polar ice caps using the Hubble Space Telescope. The idea was to force the survivors to live within his legally owned premises. Brain’s evil plan was to enslave humanity by taking advantage of the housing crisis following the apocalyptic disaster.

4 AAAHH!!! REAL MONSTERS

A still from Nickelodeon's Aaahh!!! Real Monsters

Aaahh!!! Real Monsters was another Nickelodeon cartoon that didn’t sugar coat its characters and stories. This oddly delightful and gross cartoon depicts a very macabre take on the monsters hiding under our beds. The series centers on Ickis, Oblina and Krumm who attend an underground school for monsters and perform scares on the surface.

Aaahh!!! Real Monsters has a decent amount of moments gruesome enough to make even grown-ups turn away from the TV screen. Plus, the series also deals with topics such as drugs. In one episode, Krumm gets high and starts hallucinating after digesting an air sickness bag. While, not the darkest show on the list, it’s still hard to imagine that even this would be allowed to be part of today’s kid’s program.

3 COURAGE THE COWARDLY DOG

Courage the Cowardly Dog

Courage the Cowardly Dog is an animated horror comedy series about the titular anthropomorphic pink dog living with an elderly couple. While the wife treats Courage extremely well, her grumpy husband often abuses the poor Courage. This unusual trio usually gets into creepy mishaps shrouded in paranormal phenomenon and the supernatural. The series’ atmosphere is rather grim, as is the shows surreal humor.

Courage, despite what his name might suggest, is a dog that scares incredibly easy. Unfortunately for him, he often encounters various perils such as monsters, aliens, demons, etc. And while some of the creatures the trio encounters are friendly, most are in fact hostile. Surprisingly, the cartoon was aimed at younger audiences although it featured graphic violent scenes such as exploding organs and turning inside out.

2 THE REN & STIMPY SHOW

The Ren and Stimpy Show

The Ren & Stimpy Show is a popular animated series which originally aired on Nickelodeon from 1991 to 1996. The series follows the misadventures of the emotionally unstable chihuahua Ren and the good-natured cat Stimpy. The cartoon’s use of obscene and dark humor, mature innuendo and violence locked the production staff in endless disputes with Nickelodeon’s Standards and Practices department.

The show has been known to push the boundary consistently and usually in a rather gruesome fashion. The abusive Ren would repeatedly take advantage of the dimwitted Stimpy. But, when the infamous duo returned in an adult cartoon, things got a bit out of hand. The Adult Party Cartoon showed Ren and Stimpy in a very abusive homosexual relationship. Looking back at this cartoon we can’t help but wonder, why were we ever allowed to watch this?

1 ANIMANIACS

Animaniacs

Animaniacs was an animated variety show consisting of short skits with a large cast of zany characters. Directed by Steven Spielberg, the cartoon featured a lot of recurring jokes, catchphrases and adult humor. Fun for the whole family, Animaniacs provided slapstick comedy for the kids and parody, social commentary and sexual innuendo for the parents.

One of the series recurring segments, Goodfeathers showcased characters based on The Godfather and Goodfellas, two not exactly PG-13 movies. The recurring character Minerva Mink, who was based on Marilyn Monroe, appeared only in a few segments due to her overly voluptuous nature. One of her bits had to be re-drawn and re-shot to decrease her cleavage. Still, despite its dark and adult humor, Animaniacs became the second-most popular children’s show.

So which of these cartoons did you watch as a kid? As always, let us know in the comments!