15 Terrifying Classic Cartoon Villains That Haunted Our Childhood

Classic cartoons have a lot to offer, from morality lessons, to team building paradigms, to plenty of nauseatingly cute characters. They let us follow the adventures of our favorite heroes while they get in and out of tough situations, always managing to save the day against the odds. Good always triumphed over evil, because evil represented selfishness, vanity, and what happens when you don’t get hugged enough as a child. For all their heroism and camaraderie-packed half hour time slots, classic cartoons did have a dark side.

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Whose mouth didn’t turn into a wide “O” when Megatron would swat Starscream aside without a second thought and mercilessly sacrifice his own Decepticons in the pursuit of the Autobots? Who didn’t get weirded out when Mumm-Ra, essentially a rotting corpse, would shapeshift in strength and size, or become a completely different person to deceive the ThunderCats? Who wasn’t completely obsessed with finding out just what Dr. Claw looked like, but also a little afraid to see the reveal? Presenting a list of the 15 scariest villains in classic cartoons, we’ve compiled some of the weirdest, most brutal, or just plain creepiest evildoers from your favorite cartoons to remind you that networks weren’t afraid of giving kids nightmares in the pursuit of ratings.


Some people would argue that Shredder was pretty scary in Teenage Mutant Ninja Turtles, but other than having spikey shoulder pads and being pretty jacked, he wasn’t all that terrifying. A TALKING BRAIN IN THE STOMACH OF A GIANT HUMAN SHAPED EXO SUIT HOWEVER -- yeah, Krang was the stuff of deformed nightmares.

Previously a warlord from Dimension X, when he was banished to Earth he actually helped Shredder out, since at the time he wasn’t able to defeat the turtles on his own. Krang came with a pretty sweet house, aka the Technodrome, a mobile battle fortress heavily armored and weaponized. His only goal was to rule all dimensions, including Earth, and he was only ever at the mercy of the walking exo suit that carried him (but was so often damaged). Then he would shake a furious tentacle.


The ‘90s animated Spider-Man series introduced the "Venom Saga", and it featured one of the most famous villains in comics or cartoons. The terror began when astronauts John Jameson and Paul Stevens discovered a rock called Promethium X, more powerful than plutonium. It has a sinister aspect to it, a mysterious symbiote that breaks free and tries to kill them. Spider-Man saves the day, but not without taking a little souvenir with him.

Eventually, Spider-Man finds that the symbiote can take over and bond with his suit, giving him advanced powers. However, it is unstable, and Spider-Man manages to get it to leave him with the use of extremely loud noise. It bonds with Eddie Brock, whose evil intentions align better with its powers. Venom was much bigger than Spidey, wore a black suit, and had the large unhinging jaw with jagged teeth and a Gene Simmons tongue.


Pretty much all villains are based on the Snidely Whiplash stereotype -- that is to say, the maniacal, dastardly man who plots to wound the purest of heroes by kidnapping something dear to him, in this case Nell Fenwick. In the opening of the cartoon he always chuckled fiendishly while tying her to some train tracks.

Most of the time all he really did was try to foil the Mounties, smuggle illegal goods across the border, or try to take over the Mounties’ post. But something about the little man dressed in black, with the sinister look in his eyes and the always-curling mustache sticks in your mind forver. It was said he tied women to train tracks because he literally never knew any better.


In Eternia or on Earth, Skeletor was one of the scariest things on television for children. He was huge, ripped, lusted for nothing but more power and his face was a skull. Originally just depicted as some evil demon from another dimension as He-Man: Masters of the Universe progressed, it was thought he might have even been the brother of He-Man’s father.

The species that Skeletor belonged to were the Gar, blue skinned humanoids who were almost exclusively always villains. He was once known as Keldor, apparently a rather handsome blue-faced devil, until that face was melted off. He survived, somehow able to still be alive with his skull exposed, to creep out kids every Saturday morning with his diabolical laughter.


Think what you will about Captain Planet (recycling is for cool kids!), but Lord Skumm was decidedly less campy than the rest of the cartoon. If Splinter ever got sick of teenage turtle antics and decided to become evil, he might resemble this giant rat human (Ver-Man?!). He was known for creating Rat Rot, a chemical disease that he would use to contaminate various water supplies. If you drank it, you would also turn into a giant rat human and be under his control.

Eventually, many people ended up being sick from Rat Rot (including a few of the Planeteers), and it was up to the rest of Captain Planet’s posse to rescue them and somehow reverse the effects. Lord Skumm was tall and human looking except for his long rat’s tail, clawed appendages, and sharp, needle like teeth. His appearance was enough for kids to swear off drinking water.


A bit of a mixture between Skeletor’s demonic cruelty and Mumm-Ra’s mystical menace, Skullmaster was a loathsome warlock whose only desire was to plunge the world into darkness. He destroyed two civilizations, the Lemurians and the Atlanteans, for denying him access to the secrets of the key (an actual baseball cap), and powered his Crystal of Souls with the souls of Atlantis. He sealed the reigning king Lava Lord deep underground and assumed command of his minion horde.

He is the archnemesis of Mighty Max, a teenager who, after mysteriously receiving a videotape and a baseball cap can suddenly travel through various portals through time and space. He is the “Capbearer”, mentored by a chicken creature named Virgil, and a 10,000 year old warrior named Norman. It was hard for a kid to believe anyone stood a chance against someone as imposing and ferocious as Skullmaster.


While he may not seem that gnarly, Dr. Zin was a power-hungry scientist who became more foreboding as The Real Adventures of Jonny Quest went on. The sworn archenemy of his father, Dr. Quest, Dr. Zin was constantly trying to steal his inventions and ideas.

The creepiest of these was when, while living in a volcanic mountain in Peru, he tried to clone himself because he was dying of a mysterious disease. The clones were all deformed, but he thought injecting pure gold into them would stabilize their metabolic process. That didn’t work for obvious reasons, but if it wasn’t making mutant clones it was launching squadrons of giant radioactive bugs from an asteroid fortress. Or robotic ninjas. Dr. Zin was truly the definition of a mad scientist, and terrifying because there was no scheme too extreme to try against the Quests.


If you were a young child, you probably liked the Care Bears, and you probably liked them because they were cute, cuddly and always happy. You were probably pretty freaked out by No Heart, who also appeared to have no face, just a pair of glowing red eyes, two bushy eyebrows, and a bad attitude. He clearly was not held enough as a child.

He lives in a castle in a storm cloud because of course he does, and his niece Shreeky can transform him into any animal when she shrieks, though he has no idea which one and has no control when the transformation happens. He doesn’t ever really leave the castle, is constantly grumpy, and wants to destroy all caring in the world. Oh, and eat Gentle Heart Lamb (probably with some fava beans).


Dino Riders, basically one long toy commercial that was part of the Marvel Action Universe, chronicled the battle between the Valorians and the evil Rulons on a prehistoric version of Earth. The Valorians are superhuman, while the Rulons are a mixture of humans and animal creatures. Both the Valorians and the Rulons were from the future and were transported back to the time when dinosaurs roamed the earth, which they use for transportation and as battle buddies.

The ruler of the Rulons was Emperor Krulos, another villain voiced by Frank Welker. He proposed to brainwash dinosaurs into servitude, unlike the Valorians who telepathically befriended them. He was a giant, gross frog human in an armored suit that wanted world domination (naturally). He rode a laser-mounted Tyrannosaurus into battle.


The heroes of the Lightning League -- Jayce, Flora, Herc Stormsailor, Oon, and Gillian -- were in constant combat with Saw Boss and his Monster Minds, plant-based creatures that were after Jayce’s father for causing a supernova that destroyed their home planet. The Monster Minds traveled via giant vines, which could apparently grow in outer space. Their seeds sprout into more Monster Minds.

Saw Boss wasn’t completely obsessed with revenge against Jayce’s botanist father -- he wanted to take over other planets as well, but Audric had the only means to destroy his kind (a magical root). He can communicate with any of his plant army through telepathy, can teleport his HQ, and can even transform into a tank. He looked like he had a large brain sack on the outside of his skull, and had plant tentacles running all over his body.


“I’ll get you Gadget! NEXT TIME!!” shouted the evil Dr. Claw, every time his dastardly plans were foiled by the Inspector. Every time he sends his henchman after Gadget, they always end up disappointing him, and Gadget escapes his clutches, and at the end of every episode, he has to hire new henchman.

In classic villain tradition, he’s dark, sinister and menacing, mostly because we never see his face (or the rest of his body), and only see his one metal clawed hand. He wants world power, to destroy Inspector Gadget, and control Metro City. He lives in a creepy castle, always watching Gadget on the monitor of his computer. Compared to the lighthearted nature of the show due to Gadget’s bumbling, Dr. Claw was a surprisingly dark villain.


With his glowing red eyes, gravely voice, and mummified appendages, Mumm Ra on Thundercats was one creepy rotting dead guy. Technically an evil sorcerer, he was a servant of the Ancient Spirits of Evil, entities not unlike the Four Horsemen of the Apocalypse. Bound to carry out their wicked whims, he resides in the Black Pyramid on Third Earth, hellbent on obtaining the Eye of Thundera as a source of power.

Not only was he essentially an immortal corpse, he could shapeshift, using the powers granted to him by the Ancient Spirits of Evil to become smaller or larger as needed, or even turning into something or someone else entirely. He was a masterful magic user that was practically omniscient, and he was in no way incompetent or bumbling, despite being in servitude to mystical forces.


When thinking about mob bosses, most people don’t conjure up the image of a giant ogre looking monster with a lion mane and a mouth full of shattered teeth. But that’s exactly the description for Mon*Star, Silverhawk’s main villain. Once a criminal on Penal Planet 10, he became the criminal kingpin of the Limbo Mob after his escape to Limbo, where he camped out for over 300 years.

He gets his power from the Moon Star, which includes transformation, and he’s covered in robotic armor. He has jets on his elbows to fly through space with, and he can shoot blasts of red energy. He has an eyepatch that shoots beams that can hypnotize, hold an enemy in place, or just crush them.


The ruler of the Galra Empire and nemesis to Voltron was the cruel tyrant King Zarkon. Once a freedom fighter that fought alongside King Alfor of Altea, he was seduced by the powerful substance Quintessence that promised immortality. When a comet hit the planet, it also left a rift open in its crater that allowed for creatures to come through. And though the need to attack these creatures led to the creation of the Five Lion ships that assembled to make Voltron, it also led to Zarkon being addicted to Quintessence.

When King Alfor evacuated his planet and destroyed it to close the rifts, Zarkon was outraged. He rallied his armies and killed his one time friend, and enslaving the rest. He be believes that weakness is an infection, and if even half his armies were slaughtered against Voltron, that the other half would be stronger because of it.


The General of the Decepticons, voiced by the inimitable Frank Welker, Megatron was an effective and intimidating villain. He was focused, brutal, and ruthless. More cunning and focused than anyone around him, he would stop at nothing to achieve his goal; bringing order to the universe through glorious combat. To die by his metal fist he considered a great honor.

He went to Earth to acquire Energon and use it on Cybertron to return it to its Golden Age. With himself as supreme ruler over the entire civilization. When he was mortally wounded by Optimus Prime, he struck a deal with Unicron to receive a power boost and became Galvatron, in exchange for destroying the Matrix of Leadership. In his enhanced form he was just as cruel as before, always willing to destroy other Decepticons to get what he wanted. Who didn’t feel a little bad for Starscream?

Which of these cartoon villains scared you the most? Let us know in the comments!

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