It's been a long time since audiences believed that cartoons were only for children. It's been even longer since people thought that cartoons were meant to be light-hearted. As series like Batman: The Animated Series have shown, cartoons can be dark and moody, and evoke emotions other than joy from their audiences.

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However, some cartoons choose to double down on their stories. They don't just maintain their serious tones, but raise the stakes to create a world that feels more dangerous with each new episode. The drama ramps up as the story builds to its conclusion, showing that the darkest stories can be hidden in cartoons.

10 Samurai Jack Shows A Man Struggling To Finish His Enemy As The World Gets Darker

Samurai Jack Time Portal

Samurai Jack is the story of a samurai who's training to kill the powerful monster Aku. However, when Jack is outsmarted and sent to the future, he learns that Aku has had centuries to rule over humankind. Things start out rather dark in Samurai Jack.

The last season takes this to another level. After spending years battling against Aku without getting any closer to winning, Jack finally gets the chance to succeed. Unfortunately, he does so at the cost of losing a woman he’s fallen in love with.

9 Family Guy Became Much More Violent In Later Seasons

The Griffin family sitting in front of the TV - Family Guy

When people think of Family Guy, they don't always think of dark plots. But, Family Guy sometimes cloaks its darker stories in humor. While Seth MacFarlane’s popular cartoon is the home of cutaway gags based on obscure references, it’s also gotten a bit stranger.

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Family Guy isn’t afraid to delve into some dark humor, sometimes involving gore and violence. Some scenes can be really stomach-turning, even for viewers who are normally used to the series’ adult humor. Of course, a series that’s been running as long as Family Guy has to try out new things, so maybe this isn’t something it intends to rely on too frequently.

8 Scooby-Doo! Mystery Inc Introduces Some Dark Twists Later OnScooby-Doo Mystery Inc

Mystery Inc started with themes that felt different to other Scooby-Doo series. It still maintained the same humor that fans loved the franchise for, but there was something different about the show. Mystery Inc maintained a more serial nature, constantly developing the story of the cast.

Over time, the characters eventually began referencing popular horror franchises while learning more about the secrets of their hometown. The end of Mystery Inc builds to show a threat to humanity, and the second season has an ending that has to be seen to be believed.

7 Young Justice Ventures Into Dark Territories After Learning Speedy Is A Clone

young justice phantoms

Young Justice is very similar to the DC Animated Universe in tone. While it starts by pitting the superhero against the villain of the week, the end of season one changes things up. With season one's ending, fans learn that Speedy has been a clone under the control of Vandal Savage since the beginning.

With Speedy’s help, the rest of the Justice League is put under Savage’s mind control and vanish for several hours. What happened to the real Speedy sends the clone down a dark path. Meanwhile, the League spend a season trying to make up for what they did when they were missing. Later seasons also show multiple heroes falling in battle saving the world.

6 TMNT 2003 Pushed The Limits For Saturday Morning Cartoons

Teenage Mutant Ninja Turtles

The 2003 version of Teenage Mutant Ninja Turtles was quite dark for a Saturday morning cartoon show. It opened with a darker, more serious tone than it’s 1987 counterpart, reminding everyone the Turtles can be a little gritty. Then, TMNT began adapting storylines from the comics like Gang War, where the entire city was torn apart by a war between the Foot and the Purple Dragons.

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By season four, the entire team was at risk thanks to Leo’s dark turn after their battle against the Shredder. Though TMNT embraced its comedy when necessary, it maintained enough of an edge to be approachable to an adult audience.

5 Teen Titans Forced The Team To Get Serious With The Appearance Of Trigon

Teen Titans' Robin

Teen Titans was meant to be a light-hearted alternative to the DCAU, but fans know that was never true. Teen Titans does have some over the top, anime-inspired comedy, but the show was never afraid of getting into darker elements. Slade tore the team apart and caused Robin to take on the secret identity 'Red X' without the team knowing.

Later, the team battled Raven’s dad, Trigon, who turned the entire planet into stone. Additionally, Terra betrayed Beast Boy and the team, something Teen Titans fans are frustrated about to this day.

4 Venture Bros Leaned Into Violence After Revealing Its Protagonists Were Clones

Venture Bros image featuring Team Venture

Venture Bros was originally meant to be a more mature, comedic parody of The Adventures of Jonny Quest. The series has its obvious parodies of Benton Quest and Race Bannon, and is never afraid to take some harsh shots at the original show. By the end of the first season, viewers are treated to a shocking twist: both of Dr. Venture’s sons are killed by The Monarch’s Henchman.

This felt like an admission that Venture Bros would never return. Instead, viewers learn in the next season that both Hank and Dean die frequently during their adventures, and Dr. Venture has been cloning them for years.

3 Ben 10 Gets More Serious With Each New Incarnation

Ben 10 2005 Original

Ben 10 opens with a serious quest for the protagonist to take on. While on summer vacation, Ben Tennyson finds a device known as the Omnitrix. Infusing him with the power to transform into different aliens, Ben is responsible for protecting the Earth.

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Each season of Ben 10 ramps things up a bit more. His responsibilities grow as he gets older and he finds himself going up against greater and more dangerous threats. By Ultimate Alien, Ben is dealing with magical artifacts that could wipe out the planet, and the expectations of him are higher because of his history of saving the world.

2 Batman: The Animated Series Saw Bruce Begin Pushing Away Allies

The Dynamic Duo Patrols Gotham In Batman The Animated Series

Up until the release of Batman: The Animated Series, there had never been a serious Batman in the cartoons before. Most versions were strongly influenced by the classic Adam West show, even if they didn’t directly copy it. The ‘90s series was so influential because it was the first time Batman felt as serious as the comics.

The longer Batman: TAS went on, the more fans were shown the toll of Bruce’s never-ending battle against crime. He pushed away friends and became even more distant, refusing to quit and not caring what it cost him. In the end, he becomes the man viewers see in Batman Beyond.

1 Avatar: The Last Airbender Ended With A Climactic Showdown Against Fire Lord Ozai

Avatar TLA Aang Overpowers Ozai

Avatar: The Last Airbender opens with a narration that reminds viewers that an entire nation was wiped out. This wasn't because of a natural disaster, but because the Fire Lord was terrified that the Avatar would stop him from gaining control over all the nations. That’s how The Last Airbender begins, and it doesn’t get easier in future seasons.

While the Avatar gang travel the nations trying to teach Aang how to use the other elements, the Fire Nation stays busy. With no one attempting to fight back against the Fire Lord, he captures major targets in both the Water and Earth nations. Aang’s battle against the Fire Lord happens because he’s learned all elements and because he has no choice. With Sozin’s Comet, the Fire Lord is strong enough to eliminate anyone in his way, except the Avatar.