What makes a great villain? Do they need a detailed backstory to explain their crooked ways, or are they inhuman, too monstrous for redemption? Some of the best villains of modern times come from the world of kids' cartoons, when their nefarious ways can really make an impression on young viewers. But don't be fooled into thinking that, because these villains were designed for kids, they lack the kind of complexity that makes the best villains compelling.

We've put together a list of some of the very best children's cartoon villains, and we've attempted to explain what it is about these characters that continues to scare us long after we grew out of the target audience range.

  • 10

    Jessie & James, Pokemon: Indigo League

    Prepare for trouble and make it double. This troublemaking duo debuted in Episode 2 of the first Pokemon series, and have been out stealing pokemon ever since. Well, trying really hard at it, anyway.

    Why They’re Scary

    Jessie and James fall into one of my favorite villain categories: villains that are bad at being villains. Their job is to steal powerful pokemon for Team Rocket, and they’ve set their sights on Ash Ketchum’s Pikachu. And yet, they are constantly bested by a ten year old. They clearly aren’t cut out for villainy. It’s like they’re just good guys on the wrong side, which I suppose just goes to show what good people will turn to when they feel they have no other options.

    Best Episode: 'Training Daze'

  • 9

    Plankton, Spongebob Squarepants

    This scheming, conniving, burger-stealing microorganism began as a villain, but soon became a fringe protagonist as the shenanigans of Spongebob Squarepants slowly drew him into the drama.

    Why He’s Scary

    What’s sad about Plankton is that he and Mr. Krabs actually began as friends. The episode 'Friend or Foe' details their plan to open a restaurant together until their quarrels drove them apart. As Mr. Krabs became successful, Plankton's own failure became more unbearable, warping him into an increasingly desperate and hateful creature. But his evil deeds aren’t motivated by hatred, but by desire to reconnect with who he was. Plankton’s goal isn’t to sabotage Krabs, but to steal his success so that he and Krabs might again be on equal ground.

    Best Episode: 'The Algae’s Always Greener'

  • 8

    Mr. Crocker, Fairly Odd Parents

    Denzel Crocker, a miserable elementary school teacher, is obsessed with fairy godparents after losing his own in his childhood. After learning that his student Timmy also possesses fairy godparents, he has made it his mission to reveal them.

    Why He’s Scary

    Mr. Crocker is an adult trapped in a child's world. In a literal sense, his character subverts the trope of the clueless adult found in many kid's shows. He is the only one who is aware of Timmy’s fairy godparents, and the other adult authority characters believe him to be insane. Figuratively, Mr. Crocker is unable to move past the loss of his own fairy godparents when he was Timmy’s age, and all his attempts to regain them throughout his life have resulted in repeated humiliation and despair.

    Best Episode: 'The Secret Origins of Denzel Crocker'

  • 7

    Him, Power Puff Girls

    The evilest of evil, the cruelest of cruel, with a name too vile to speak. This androgynous incarnation of the devil seeks to destroy the world... because he can.

    Why He’s Scary

    Him likes to play games with people. He is evil and diabolical, but only on his terms. In fact, when he’s not fighting he is incredibly polite, learns from his mistakes, and doesn’t pick fights that aren’t worth his time. Most of his attacks are psychological: in his first appearance in 'Octi Evil', he possesses Bubble’s toy octopus, taking advantage of her gullibility, and in 'Tough Love', he forces the girls to fight their loved ones, who he has turned against them.

    Best Episode: 'Custody Battle'

  • 6

    Harley Quinn, Batman: The Animated Series

    Since her debut in Batman: The Animated Series, Harley has become one of the most notorious DC villains. She has since infiltrated the Batman franchise, appearing in dozens of shows, films, games, and comics.

    Why She’s Scary

    While Harley Quinn is by no means helpless, everything about her origins embodies the fear of helplessness. After interviewing the Joker early in her career as a psychiatrist, it seems that she is unable to resist him and instead frees him from Arkham. This continues as it is revealed that the Joker is cruel and abusive towards her. However, it is impossible for Harley to return to her old life, as that would involve admitting to herself that she gave up everything she had for a lie.

    Best Episode: 'Mad Love'

  • 5

    Bill Cypher, Gravity Falls

    In a show that is characterized by its use of codes and ciphers, it only makes sense that the antagonist would use these as tools to manipulate the multiverse.

    Why He’s Scary

    Bill is all about illusion and mind games. He is the evil of every cautionary tale of genies: he possesses great power that he claims can benefit those who aid him... but he uses all the usual caveats to trick those around him into doing his bidding. He has attached himself to the Pine family, and it is suggested that he has sinister plans to use them for the destruction of the universe. He is not above manipulating and harming children; Mabel and Dipper are just a means to an end for him.

    Best Episode: 'Sock Opera'

  • 4

    The Beast, Over the Garden Wall

    Over the course of ten episodes, it is revealed that the Beast is the source of the evil in the forest. He is the poison that slowly clogs its veins, choking out any goodness left with fear and luring the innocent to their doom.

    Why He’s Scary

    The best horror uses lack of information to its advantage. We don’t know where The Beast comes from, or why he needs to steal the souls of children to keep himself alive, and our inability to answer these questions deprives us of any point of relation or understanding. Pair that with his sinister baritone, joyless singing, and shadowy manipulation, and you have an eerie monster that might convince you to dig out your childhood nightlight.

    Best Episode: 'The Unknown'

  • 3

    Demona, Gargoyles

    In an attempt to rid her gargoyle clan of the humans at Castle Wyvern, Demona betrayed her castle to the Vikings, which resulted in the destruction of her clan. When those who remain awaken 1000 years later, Demona is determined to justify her actions and end the humans once and for all.

    Why She’s Scary

    Demona’s hatred of humanity is rooted in her own sense of superiority; to her, the mere existence of humans is an insult. She becomes increasingly frustrated as her former mate Goliath continues to thwart her plans, and it becomes clear that she must choose between her clan and her hatred. But she has displaced all blame for her own faults onto the humans, and her loathing is driven by a fierce desire to make them pay for her own mistakes, to seek vengeance for an imagined slight against her people. This makes it impossible for her to admit that she is the source of her problems, a reality that only fuels her anger.

    Best Episode: 'City of Stone'

  • 2

    Azula, Avatar: The Last Airbender

    Crown Princess Azula of the Fire Nation desires power above all else. To achieve this end, she will sacrifice friends and family, and will destroy anyone who gets in her way.

    Why She’s Scary

    Azula has internalized the teachings of her demanding, abusive father. At fourteen, she is extremely powerful, as she uses her jealousy, perfectionism, and fear of failure to fuel her abilities. She does not acknowledge that her inability to empathize is also a result of her father’s abuse, choosing instead to use fear and intimidation to further her interests.

    Best Episode: 'The Beach'

  • 1

    The Lich, Adventure Time

    A demonic nightmare creature, the Lich is the source of all evil. Even incarnated in the body of an infant, the Lich is capable of emitting nightmare toxins that send tremors through the heart of even the strongest hero.

    Why He’s Scary

    If ever there was real nightmare fuel in a kid’s show, this is it. The Lich has zero redemptive qualities, and doesn’t need to rely on tricks or manipulation to get what he wants: the destruction of all life in the universe. What’s even more unsettling is that the Lich’s evil still exists inside the innocent Sweet P. While it seems Sweet P can contain it, unaware that it is anything more than a dream, it still creeps out when he is feeling threatened. It’s disturbing to think that this sweet child could become the epitome of evil at any moment, or that the Lich might once again emerge, leaving the empty husk of Sweet P behind.

    Best Episode: 'Gold Stars'

  • *

    Bonus: The Best Adventure Time Fan Art Ever

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