Teens Are Monsters



"They say that teenagers scare the living shit out of me

They could care less as long as someone'll bleed"

- My Chemical Romance, "Teenagers"

In their strain to try and be taken seriously, teenagers are susceptible, gullible, and downright dangerous to anyone who wants to manipulate them. These are the best targets for demons, vampires or The Virus. Sometimes they're just delinquents with no respect, but are only a hair's breadth of sanity from shooting up an entire classroom, especially if you call them Just a Kid.

Much of this trope is fueled by a distrust in teenagers by the adult population. Not to mention, many parents of young children dread the moment when their innocent little angels become sassy, hormonally-imbalanced drama-magnets. However, television producers are often worried about offending the very lucrative 15- to 27-year-old market, so we'll usually see that the heroes are also teens, or at least one very "good" prominent one.

Ironically, the much milder version of this trope occurs with shows aimed toward younger children, who find teenagers cryptic, pushy, and intimidating for other reasons.

Some cases of Royal Brats can be attributed to this Trope. This Trope may also be lampshaded further still by invocations of how the teenage monsters in question used to be sweet kids. If teen monsters run society, it's a Teenage Wasteland. See also Big Brother Bully.

Of course, this can be, on an individual basis, Truth in Television; there are monster teens in Real Life in the same fashion that we can find some mean kids and cruel adults. The mere fact of being a teenager doesn´t make people automatically good or evil; it does, however, make any given person more susceptible to reckless or selfish behavior than they otherwise would be as an adult, for biological reasons. This makes it all the more commendable and impressive when a teen acts maturely, responsibly, or selflessly in situations where it would be difficult or unexpected for an average adult to act that way. Still, no personal examples, please.

Anime & Manga
"Gostumon: Woah! I think you knocked over a monster!
 * Mohiro Kitoh's manga titles tend to take a very dark view of teens and tweens. The best example would be Naru Taru, in which strange creatures called "dragonets" partner up with certain children, most of whom have issues with the way the adult world works, conferring upon them considerable power. Unlike other Mon-themed manga where that power would be used to protect Earth from alien or supernatural threats, many of the children become the threat themselves, turning their dragonets on each other and the adult world with horrific results.
 * Mohiro Kitoh's manga titles tend to take a very dark view of everything.
 * To the degree that, when Kitoh announced his next work would be a sports series about a high school girl doing mountain bike riding, the internet immediately turned to constructing scenarios about how the bike would be used to destroy the world.
 * Akira has some great examples of this trope (with Tetsuo's being the most dramatic and disturbing).
 * Akira manages to both play this trope straight and deconstruct it. Whilst Kaneda and his gang are portrayed as teenagers that have little regard to the law, they are also shown as having a sense of honor (though it is small), particularly with Kaneda's feelings toward the death of a friend (in both the anime and the manga). By the end of the series, they actually.
 * The teenagers in Battle Royale are forced to become monsters and kill each other. Some take quite easily to this new role, others never do.
 * While not necessarily teenagers, most antagonists in Yu-Gi-Oh were in their early twenties or earlier when they started out, and were at that age once the feces hit the fan. There was Pegasus at age 22 when we first saw him, there was Malik/Marik who was a mere 16 when we saw him (and who had started down the path of evil before entering puberty), and Dartz who started at only age 21, and kept himself that way for who knows how long, and Yami no Bakura, who probably wasn't more than 20 in the original timeline. To say nothing of all the other minor antagonists over the course of the story that were never older than 25, teenagers must get a horrible reputation in their world.
 * Prior to Duel Monsters taking the priority of the series, Yugi went through a whole series of teenage monsters every chapter in the manga, Seto Kaiba being among them.
 * Of course, this didn't stop at the first series either. In GX, the majority of antagonists of the day were fellow teen schoolmates, the chief antagonists of season 2 were all early 20s or younger, and season 3's subplots and season 4's plot were all ultimately instigated by youngsters.
 * Avoided in the third series Yu-Gi-Oh 5 Ds, mostly. While Aki is only 16, and goes on to terrorize Neo Domino as the Black Rose Witch and gets called a monster, all of the Dark Signers are adults.
 * Lampshaded in Digimon Adventure by Gotsumon and Pumpkinmon, despite the fact that teenagers are usually minor characters:

Pumpkinmon: Even worse! I think I knocked over a teenager!"


 * Made better by the fact that the Digimon are, well, monsters in the literal sense.
 * All the contestants in the tournament in The Law of Ueki are supposed to be junior high students. Yet, they do not mind using their powers to Take Over the World, and hell, apparently don't have any qualms about killing their opponents, for God's sake.
 * Strongest Legend Kurosawa uses this a lot, and at one point even compares them to animals.
 * Miki from Aishiteruze Baby gets bullied by her classmates after she walked in on her teacher and her teacher tells everyone else "Pick on Miki. Get grades". Granted, one could make the claim that it's the teacher who's monstrous, but the classmates still went along with it.
 * Arisa (actually her twin sister Tsubasa in disguise) has been ostracized, drugged underwater, beaten, and pushed off a cliff, among other attacks by her classmates, because she's trying to find the "King" who has an almost hypnotic hold on her sister's class. Tsubasa/Arisa's friend who previously lost faith in the King was ostracized and Driven to Suicide and is now paralyzed (it appears to be psychosomatic), but after finding out about Tsubasa being Arisa, she beat Tsubasa's aunt unconscious.
 * Glemmy Toto of Mobile Suit Gundam ZZ is a 17 year old Ace Pilot and The Starscream to Big Bad Haman Khan who gets up to some truly nasty stuff over the course of the first Neo-Zeon War, eventually forming his own faction. Whether he's a Smug Snake or a Magnificent Bastard is a matter of some debate amongst the fandom, but the fact that he's a serious problem, despite his youth, is not.
 * Carris Nautilus of After War Gundam X is a 15-year old boy who is willing to use increasingly extreme measures to bring the world under control. He eventually wises up. Shagia and Olba Frost, on the other hand, a pair of 19-year old Ace Pilots do not, and their Wangst over how unfair life is treating them nearly triggers an utterly devastating war.
 * Shinn Asuka of Mobile Suit Gundam Seed Destiny is hardly evil, but as a young, impressionable, and emotionally damaged teenager he easily falls victim to Chairman Durandal's toying with his emotions, and is used as the Chairman's attack dog for much of the show.

Comicbooks

 * In the graphic novel Black Hole, teenagers are being afflicted with a mysterious STD that causes them to mutate randomly, occasionally turning them into literal monsters: barely human creatures that live in the woods. At least some of them seem to have become significantly mentally deranged because of this, turning them into more traditional monster teens.
 * This was America's prevailing attitude towards Young Justice in The DCU, causing them to eventually become America's most wanted super-group, despite the fact that they were actually pretty heroic and set a good example for others like them.
 * The X-Men and other Marvel Mutants literally exemplify this trope. Most mutant powers seem to manifest around puberty, and turn their recipients into freaks or outcasts of some sort.
 * Elizabeth of Gemini Storm was recently revealed to be one of these, spending her teen years in juvenile hall and mental hospitals until government funding ran out from the quarantine and the institutes closed down.

Film

 * Mark Collins in Twisted.
 * The first Teenage Mutant Ninja Turtles movie used disaffected youths to form a thieves' guild.
 * From MST3K: Kitten With a Whip, I Accuse My Parents, The Sinister Urge, The Violent Years, What About Juvenile Delinquency (short) and Teen-Age Strangler
 * Also Welcome to The Dollhouse.
 * The classic horror film I Was a Teenage Werewolf took this quite literally.
 * Eden Lake takes this to a truly disturbing level.
 * Battle Royale takes this to an extreme. After children in Japan start refusing to go to school, the government starts kidnapping entire classes of teenagers, putting them on an island, give them guns and other weapons, and tells them to all go kill each other, last one alive gets out free. Many of the teens, instead of fighting against the government, see this as an opportunity to wreak havoc, and start mercilessly killing off their classmates.
 * Lets not forget the films of Larry Clark; Bully, Ken Park and Kids. Ken Park features (NSFW)
 * A big part of Brick.
 * Similarly, the film Kidulthood, being centered around the troubled youth of urban London, feeds off of this trope - even a fair few of the protagonists are pricks to some extent, while the main antagonist is a towering Jerk Jock who batters his girlfriend and shows no visible regret at leading a bullying campaign against a girl at school which ultimately drove her to suicide. Combine this with the film's other underlying theme of Adults Are Useless, and you get a pretty bleak movie.
 * Murder By Numbers, what with its vague inspiration from the Leopold and Loeb case.
 * The first two Pumpkinhead movies pretty much define this trope, with Blood Wings pretty much having you want the titular monster to pretty much slaughter every teen we meet in the movie.
 * The feral chavs terrorizing the Council Estate in Harry Brown.
 * Subverted by the kids in Attack the Block, who are first shown mugging a woman but become heroic after they team up with her after aliens attack.
 * The Pioneers in Scarecrow who traumatize Lena and her grandfather, driving them to madness and out of town.
 * The Fifties was rife with films with this at it's core with titles like "18 And Anxious". Rebel Without a Cause came in and set it straight.
 * Mildred Pierce's daughter.
 * The Texas Cheerleader Scandal: A Lifetime movie which was based on a true story.
 * Odd Girl Out: Another Lifetime Movie. In this one, the protagonist is bullied both inside and outside of school to the point where she cuts off her own hair (after the other teens say her hair is too frizzy) and overdoses on sleeping pills. Even after her attempted suicide, the kids would not ease up on her. They posted a video of her being wheeled into an ambulance on a hate page that was dedicated to her and called her a "pathetic druggie".
 * "Thirteen": With all the drug usage, underage drinking, underage sex (and numerous other illegal acts) that goes on in this movie well... lets just say this film is a parents worst nightmare on what will happen when their sweet little angels become teenagers.
 * The events of the 2008 film Red are kicked off by three teenagers mugging an old man, then shooting his dog For the Evulz.
 * The Last Exorcist's Caleb is rather creepy and antagonistic.
 * The Class (2007) is a brutal and realistic look at this and the effects it can have on someone.

Literature

 * Jodee Blanco's memoir of recovering from intense bullying, Please Stop Laughing at Me, turns both this and Kids Are Cruel Up to Eleven. A group of kids Jodee was friends with in a new town fall out with her after she refused to play a prank on a disabled teacher. They then come back to her over the summer, invite her to play baseball, then knock her out with a fastball, moon her, and call her a variety of names. Not only that, her crush wrote in her yearbook, gets beaten up by the entire football team, and is made fun of when word gets out that, and that's not even the half of it.
 * Speak has Melinda's classmates. Heather jumping ship on her. Those kids at the pep rally..
 * A Clockwork Orange in all its horror show entirety.
 * "Horrorshow" means "very good" there.
 * Figures rather prominently in many novels by Stephen King - one almost suspects King believes Teens Are Monsters himself. Among other examples, we have:
 * Todd Bowden from Apt Pupil, the second novella from Different Seasons. Todd learns that his elderly next-door neighbor is a Nazi fugitive, but doesn't turn him in because he wants to learn the "gooey stuff" about the Holocaust. As his Odd Friendship with the Nazi continues, Todd graduates from dreaming about raping concentration camp inmates to becoming a hobo-mauling serial killer. Finally,.
 * Buddy Repperton in Christine. Arnie Cunningham doesn't qualify quite so much due to the whole Demonic Possession thing.
 * The Children of the Corn.
 * Junior Rennie and his posse in Under the Dome. Three of them rape a girl while the only female member of the posse cheers them on, and Junior repeatedly has sex with the bodies of two girls he murdered and stuffed in a pantry.
 * The teenagers who in Cell.
 * The Kid in The Stand gives the appearance of this, but is in his mid twenties to thirties.
 * Henry Bowers and his friends Victor and Belch in IT, as well as Patrick Hockstetter, whose actions even disturb Henry.
 * The girls in the locker room in Carrie, particularly Chris, who comes up with the whole ill-advised pig-blood thing.
 * King taught high school for several years. He knows these people
 * Ray Bradbury loves it. Plays part in many short stories.
 * Joffrey Baratheon from A Song of Ice and Fire is only 13 years old, yet is regarded by many as the single most depraved character in the entire series.
 * In John Saul's House of Reckoning, the main character is crippled from a car accident and the entire school (not to mention the entire town) whispers behind her back and alienates her, then accuses her of worshiping the devil. Because she has a limp.
 * Saul actually has several novels with outcast teenagers being victimized by their monstrous peers. The Unwanted, Black Creek Crossing and Punish The Sinners are a few examples. Then there's Teri, the glamorous teenage serial killer in Second Child.
 * In Andrew Vachss's Burke books the protagonist often passes by disaffected teens who may be violent, though they're rarely the focus.
 * Brought up in Discworld, but in typical Pratchett fashion, quickly subverted soon after. The Ankh Morpork teen street gangs are mentioned to be ruthless and deadly... but find themselves helpless to resist Captain Carrot's good-natured effort to organize them all into a Cub Scout equivalent, camping trips and chanting all included.
 * Gone, by Michael Grant. Partially justified in that the series uses an Only Fatal to Adults situation and every main character is 14 or 15 years old. On the other hand, there are a lot more villains than heroes, and even the "good" characters have issues.
 * In The Butterfly Revolution, John Mason rapes one of the female campers, Blackridge tortures Divordich, and
 * Draco Malfoy from Harry Potter, and his Slytherin cronies. Also, the young Tom Riddle, who
 * For that matter, James Potter and Sirius Black were examples of this trope regarding Snape, at least during fifth year.
 * Snape might be an inversion because, while he didn't even seem to be mean, he had a very dark mind, with his fascination with the Dark Arts and the creation of many violent spells. This is likely what his classmates' perception of him was.
 * And Dudley before the Dementors.
 * This is, essentially, the point of Sergey Lukyanenko's Knights of Forty Islands, where a bunch of teenagers are kidnapped by aliens and put on small islands connected by narrow bridges, where they're given anger-activated swords and told that anyone who conquers all 40 islands gets to go home . The protagonists decide to make an alliance with the neighboring islands in order to peacefully or forcefully bring all islands under one rule. While it works for a short while, teenage hormones soon take over, and the alliance falls apart, as many of them just want to have power and sex (two of the betrayers are murdered in cold blood by the protagonist after they rape a girl).
 * In Darth Plagueis, it is revealed that Palpatine, as a teenager, ran over two pedestrians with his speeder and then ''told his father he wanted to be a racer. And Plagueis didn't need to give him a big nudge to get him to murder his folks. He pledged himself to the Sith at seventeen.
 * Pollyanna subverts this about as hard as possible.
 * Pollyanna subverts this about as hard as possible.

Live-Action TV

 * Buffy the Vampire Slayer. Often literally.
 * Jesse, Theresa Klusmeyer and Harmony got turned into vampires.
 * The Pack: Hyaena-possessed bullies
 * Marc the Demon
 * The Inca Mummy
 * The Swim Team
 * Pete Clarner
 * Vamp Willow and Vamp Xander
 * Faith, until her redemption
 * Connor in Angel is a perfect example. The bad guys hardly have to break a sweat to manipulate the kid into doing really nasty stuff. Fortunately, he returns in Season 5 as a much saner person, due to
 * The Middleman plays with this trope. In one episode, it appears that a teenage Stalker With a Crush girl is following her favourite boy band group, opening vortexes in physical space and is about to end the world. Turns out,
 * Kevin the Teenager in the Harry Enfield and Chums sketches. ("That is SO UNFAIR! I HATE YOU!") However this is more along the realistic lines of making him an unbearable, moody, whining brat who hates everything his parents do or say and is entirely controlled by hormones and current trends.
 * In the earlier Harry Enfield's Television Programme, Kevin (also called "Little Brother") was a hyperactive and relentlessly cheerful preteen. The first episode of ...And Chums showed his thirteenth birthday triggering a hideous Transformation Sequence, similar to Doctor Jekyll, in front of his horrified parents.
 * The Late Show with David Letterman amplifies this trope to its comic extreme in its Dwight the Troubled Teen skits. At the slightest provocation, Dwight loudly proclaims his hatred for his family and storms off.
 * Any episode of Star Trek, The Original Series (TOS) that featured anyone younger than 20 years old adheres strongly to this trope. In no fewer than three episodes (Charlie X, Miri, And The Children Shall Lead) unsupervised youngsters nearly destroy the Enterprise and/or kill the principal characters.
 * Let's not forget our friend Trelane, the teenage omnipotent being who'll hunt you down if you ruin his fun.
 * Though he was 'born' within the run of the show, Q's son of Voyager was always depicted as a teen whenever he made an appearance.
 * In contrast, Naomi Wildman follows the same path of being born during the show's run, but was depicted as a child when she interacted with the crew.
 * The first couple of seasons of Without a Trace seemed to be dedicated to the idea that teens were vicious amoral beasts who lived to victimize each other. Co-incidentally(?), CSI went through a similar phase about that same time.
 * The Sontaran Strategem, an episode of Doctor Who, features a genius teenager as an antagonist whose motivations can be boiled down to being a teenager. However, he came around in the end, sort of.
 * Also, he had gathered a large number of other genius teenagers to him who, on hearing his real plan, were appalled and immediately abandoned him. It implied that his plans were less about his age and more that he was somewhat unstable anyway.
 * Several Life Time Movies portray any teenager who's not a Naive Everygirl or a squeaky clean Mama's boy as evil, rotten assholes or bitches who try to corrupt the good kids.
 * Early on in Andromeda, the ship docked at a station run by a tribal society of teenagers (everyone died young due to radiation poisoning, so the oldest survivor was sixteen). When the teens gained access to star-destroying bombs, they immediately went out and blew up inhabited solar systems with them.
 * Pretty much the entirety of The Tribe cast at some point, but particularly the Locos, the Chosen, and the Technos.
 * The House episode "The Jerk"'s patient of the week was a teen Jerkass that bullied his mother, insulted everyone he met just for the lulz, and was just a general all around brat (after getting tired of all the tests, when asked for a urine sample, he pissed on the floor). his mother even used the "he used to such a sweet kid till he became a teen" line. House only had his Eureka Moment discovery of the kids illness by realizing that
 * Of course, he also said it was probably the mother's fault, which usually is in more real cases of bullying or teenager rebelty.
 * Though not all, a lot of the meteor freaks of the week, people who usually go crazy and start killing people on Smallville, are teenagers. Part of that is likely due to the high school/college setting of the first five seasons, but it holds true in later seasons as well.
 * Initially an Enfante Terrible, Lx-15/Alexander Luthor plunges headlong into this trope, after he ages to the point where he's in his mid-teens. He attempts to assassinate Martha Kent, Clark, and Earth-2 Lionel, burns down Luthor Mansion, and even attacks Tess, his Parental Substitute. Thank god that memory loss, and a Heel Face Turn set in.
 * The Law and Order franchise is fond of this one -- if there's a teenager in the episode, this trope trumps even Narrowed It Down to The Guy I Recognize if you're trying to guess the perp at home. Especially if it's a teenage girl. Bonus evil points to a girl in SVU who.
 * Totally subverted by the Power Rangers, where just about every teenager the audience sees ends up being unbelievably wholesome and respectable. Even the bullies and teenage-jerks usually turn out to be decent people when push comes to shove, although once every few seasons, a teenage character plays the trope straight.
 * Lampshaded in the pilot episode; the original team is assembled when Zordon looks for "immature, overbearing humans" to fight evil. This was rephrased as "teenagers with attitude" in the opening credit sequence.
 * Judge Judy is a staunch believer in this trope, for better or worse. To be fair, though, most of the teenagers that appear on the show don't really do much to dissuade her of this opinion.
 * Judge Hatchett, a courtroom show that ran from 2000 to 2008, is somewhat of an inversion. Judge Glenda Hatchett tried many cases involving out-of-control teens and tried to get them on the right road through unique interventions, with varying levels of success. Contrary to Judy, Hatchett was an advocate for kids, often saying, "If we want our children to do right, we have to do right by them."
 * SCTV did "Nice Kids From Hell", a parody of 1950s juvenile delinquent movies, where a group of clean-cut, polite teens terrorize a middle-aged couple with their pleasant, helpful behavior.
 * Subverted somewhat in Teachers, in which the titular teachers, most of whom loathe their jobs, believe this about the teenagers they teach - but their actual interactions witht hen show that the teachers are more at fault than the teens. However, background events in any given hallway or yard scene do tend to show students casually setting each other on fire or hanging each other out of windows as the teachers walk by obliviously...
 * Accepted as a truth universally acknowledged in Glee, where it ends up being true at one point or another not just of the general school population but of almost every single one of the teenage protagonists too. So far Mike Chang is about the only one who's escaped it. The trope is taken to its furthest extreme in 2X01, in which Rachel is so jealous of an exchange student's superior singing voice that she sends her to a crack house instead of an audition. It is, however, also deconstructed somewhat with the implication that what lets teens be monsters is adults not doing the job of teaching them better: WMHS has an anti-bullying policy that is not enforced, but Dalton Academy for Boys features an enforced anti-bullying policy and Teens are emphatically Not Monsters there.
 * The highschool students attending campus for a program to earn college credits in Community episode The Art of Discourse wont stop MERCILESSLY hounding the cast for going to a community college, when they'll be one day going to universities. Strangely Up to Eleven - many fans felt they were too cruel to be funny.
 * In Madeas Family Reunion, the teens and young adults at the titular reunion are called out on their bad behavior, which included gambling, dressing inappropriately, and gyrating on each other.
 * Parodied in Father Ted with the teenaged Father Damian, Evil Counterpart to Man Child Dougal. He exhibits all the typical traits (and rebels against the older priests whom he sees as his parents) and his theft of an old whistle sends the inhabitants of Craggy Island into a downward spiral of paranoia.
 * Todd and The Book of Pure Evil. Crowley High may be a Weirdness Magnet because of the wishes granted by the Jackass Genie Artifact of Doom mentioned in the title, but the book can't really be blamed for the students' tendency to kill the wishmakers... and only a couple wishmakers can be said to have had it coming.

Music

 * My Chemical Romance's The Black Parade features the song "Teenagers", which starts off about how adults view teenagers, and then how, with the way school life has changed in recent years, why it's understandable they think this way. The end message seems to be that it's a vicious cycle.
 * Thinking of the The Black Parade, let's remember The Daily Mail's scare over "the sinister death cult of Emo" which could be recruiting your children to "join the Black Parade", or in other words, kill themselves.
 * Sort of ironic when you consider that the song The Black Parade was about someone coping with the death of a loved one (his father) and the painful realization of human mortality. Still, some people (especially younger teenagers) probably didn't get the intended message out of it and thought that it was glorifying death. At least one young girl did commit suicide after listening to the album, although she most likely had severe problems long before hearing it.
 * If hearing an album is enough to cause her to end her life, stating that she had previous and severe problems is somewhat redundant.

Videogames

 * Played straight and subverted hard in Knights of the Old Republic. The cadets at the Sith Academy are early 20's at best, and indulge in things like beating up passers-by, and playing cruel tricks on the "hopefuls," like telling them to stand until they drop of exhaustion or starvation.  is a fabulously short-tempered brat who will try to skewer   on a lightsaber if you choose the wrong dialogue option. Subverted hard in that   isn't a bad guy, just unaware of other options, and that Mission Vao is higher on the Karma Meter than the party's Jedi because of her optimistic, trusting nature.
 * And to top it off, Mission is of the scoundrel class.
 * Yume Miru Kusuri. Aeka's route. When the Alpha Bitch isn't ripping up all her tuition money or convincing her boyfriend to rape the poor girl, her classmates are all tasering her in the middle of class.
 * Bully gives you the chance to play as a pubescent terror. Student looks at you the wrong way? You can shove him to the ground. Nerd bumps into you in the hallway? You can knee him in the balls. Preppy student mocks your clothing? You can shove him through a glass window, beat him with a cricket bat, and repeatedly stomp on his head while he lays moaning on the floor.
 * Subverted in that the main character can be played as a compassionate teen and actively protect vulnerable students.
 * Mass Effect averts this completely when you rescue the remaining students at Grissom Academy. The biotic students, all late-teens or very young adults, act like a family, and are all training to fight the Reapers on the front lines with their gift-abilities, knowing quite well how dangerous it is to do so. In fact, if you order them to act in a support role in the war (forming barriers for troops on or near the front lines), they'll protest it, but follow along the order. Regardless, they sometimes have to act offensively in self-defense even in the support role, and save a ton of lives with their actions, not complaining at all during their service in a particularly hellish war. The savants and intellectual geniuses of the Academy also act fairly mature and contribute wholeheartedly to the Crucible Project. There's also an 18-19 year-old kid who eagerly volunteers to sign on as a single-mission freelancer for a mercenary group, equipped only with a cheap pistol. You can break his gun, which he'll later deeply thank you for after seeing news reports of every single mercenary who participated in the mission ended up dead, telling you that he won't waste the chance you gave him. Or, you can tell him where to sign up, and you later see him casually sniped by Garrus as he assaults the base along with the rest of the mercs. This is in a series that doesn't hesitate to show people of all races, genders, affiliations, and cultures acting nobly or monstrously and everything in between.

Webcomics

 * Jeffrey Rowland in this strip seems to be subverting this, and then says in the alt text, "When I was a teenager I probably should've been put in prison."
 * This Goblin Hollow strip subverts it in RH Junior's favorite way
 * About half of Homestuck's six-sweeps (thirteen years)-old Troll characters qualify. Specifically Vriska Serket, Eridan Ampora.

Web Originals

 * In Survival of the Fittest, some of the high-schoolers thrown into the game prove to be capable of horrifying acts of brutality, though many of the more violent ones are already totally insane, and a few are thrown onto the island from insane asylums and the like specifically to spice up the game. Even with that in mind though, the kids almost seem worse than the terrorists who abduct them.
 * Whateley Academy has what might seem to be more than its fair share of students who fit this trope. Possibly justified, though, in that it's presented as pretty much the only school for teenage mutants in the entire US (if not much of the world, given the number of foreign students showing up) -- there just aren't that many other places for the offspring of infamous supervillains, the badly traumatized, and the just plain assholes among them to go, so Whateley quite naturally becomes the place where one almost by default encounters all of them at once.
 * A lot of Protectors of the Plot Continuum are in their teens, and committing acts of extreme violence is all part and parcel of the job.
 * Any memory that The Nostalgia Critic seems to have of high school involves some sort of bullying. In his Doug's First Movie review, he loses his temper at teen girls thinking the monster dressed up as female is cute, when in reality they cause so many body issues in each other.
 * The Nostalgia Chick was a Bratty Teenage Daughter when she was younger, and got bullied so much in school that she tried to take the "fur and limo" type of revenge at her Class Reunion.

Western Animation
"Hank: You were right, Bill. Teenagers are cruel. They'll pick on the slowest, heaviest... Well, the important thing is, you were right, Bill!"
 * Codename Kids Next Door follows the milder version of this trope. It couples Adults Are Useless with the dubious situation of teenagers being loyal minions, perhaps based on the logic that teenagers actively try to behave like adults.
 * Although they also betray the adults as well, possibly in reference to the fact that teenagers are also more rebellious against adults than kids are (or just to show that they are indeed bastards).
 * Many characters in the show enter an "outgrowing" phase shortly before their 13th birthday and become the rebellious bastard stereotype we know and love when the finally hit the big 13.
 * Superman: The Animated Series had an episode where Granny Goodness created a crime syndicate out of wayward teens in Metropolis, using Apokoliptian technology, love, and twisted sadism.
 * Parodied in Animaniacs via the Katie Ka-Boom shorts which took it to outlandish extremes; Katie literally turns into a monster whenever she's upset.
 * Katie's issue was implied to be a much more specific teen problem.
 * Two episodes of Powerpuff Girls featured the Smith family, one member of which was their angry teen son Bud. The first episode, Bud's entire appearance consisted of him yelling something typically teenagerish at his father, such as "I hate you!" and "No one understands me!" The second episode, which features the entire family as villains, provides every member of the family with a motivation for why they hate the Powerpuff Girls - and Bud's is "I hate everything!"
 * There's also the Gangreen Gang, who are literally teenage monsters.
 * Vicky, who is pictured above.
 * She's consistently painted as a evil babysitter, but it only brings up her age when Rule of Funny applies. More than likely that she has always been and will always be evil. Her age is a side-effect of being a babysitter.
 * In one episode she's member of a whole club of evil teen girl babysitters. But it's not likely they'll be brought up again.
 * American Dad parodies this, showing a pubescent Haley as a destructive monster whose parents have to get improvised weapons to deal with.
 * Azula of Avatar: The Last Airbender is nearly the lone exception to an otherwise subverted rule.
 * Probably the next most prominent example is Jet, who attempts to kick an old man in the head and flood a whole village of innocents in his intense rage towards the Fire Nation. He's the leader of an entire gang of teenagers willing to commit murder and other dark crimes for no other motivation than revenge, and even gets called a monster in-universe by Katara. He's changed his approach by the next time we see him, insisting that nobody else will get hurt when he tries to expose two firebenders disguised as Earth Kingdom refugees, but is forced to learn that  when his plan backfires on him.
 * The vast majority of villains on Static Shock are superpowered teenagers.
 * As are the heroes.
 * Ditto for Batman Beyond.
 * Kevin 11 of Ben 10 is an interesting inversion, in that he was an Azula-level Ax Crazy Enfante Terrible sociopath as a preteen kid, but calmed down into a genuinely heroic Jerk With a Heart of Gold by the time he actually became a teenager.
 * Mac's 13-year-old older brother Terrence in Fosters Home for Imaginary Friends. In the pilot (along with Duchess), he and her plan to kill Bloo, and most of his life is devoted to making Mac's life a living Hell.
 * One episode of King of the Hill has a gang of teenage paintball delinquents making Hank and his buddies' life a living hell (to the point of doing drive-by shootings with the paintball rifles) just because he took a stand for Bobby earlier. The trope's even mentioned when they get Bill to pull a Wounded Gazelle Gambit so Hank and Dale could pick off two of them:
 * One episode of King of the Hill has a gang of teenage paintball delinquents making Hank and his buddies' life a living hell (to the point of doing drive-by shootings with the paintball rifles) just because he took a stand for Bobby earlier. The trope's even mentioned when they get Bill to pull a Wounded Gazelle Gambit so Hank and Dale could pick off two of them:

Real Life

 * Now science gives some credence to Teens Are Monsters: the frontal lobe of the human brain is not fully developed until the mid-twenties., . This explains why teenagers tend to engage in risky behaviors and go to extremes. This does not, however, give teens monstrous or evil tendencies; it merely devalues and muddles the perceived risks of an action, as well as the potential negative consequences. It's when this is combined with high social pressure, the extremely confusing and paradigm-shifting development from child into adult and dependency into independence, major hormonal changes, and the EXTREMELY confusing and new subjects of sexuality (or at least sexuality in relation with romance and sex), attraction, and sexual orientation (even for hetersexuals, yes) that teenagers are most prone to bad or reckless actions. Realistically speaking, teens are more like victims to a perfect storm of environmental and biological developments that pile on top of each other. Notably, there are many, many teens who subvert and avert this trope altogether, even when severely handicapped in the ability to see and understand the consequences and perspectives of situations and actions, as well effectively empathize with others in many situations (futilely struggling to understand oneself with a constantly changing self makes effective empathy difficult, like trying to hit a distant target with an uncalibrated gun that is constantly recalibrating itself randomly and in new ways).
 * There was a spate of mass shootings at American high schools in the late 90’s, culminating in the Columbine massacre of 1999. Although high school violence had been common in inner cities, the West Paducah, Jonesboro, Springfield, Oregon, and Columbine shootings startled the USA because they took place in otherwise quiet rural or suburban schools, and they targeted the student body as a whole instead of an individual whom the shooter hated for a particular reason.
 * The main factor that made the Leopold and Loeb case so sensational in the 1920s (apart from the fact that, well, they were both kind of gay) was that they were both intelligent, well-off, and 18-19 years old.
 * Leopold and Loeb were also famous because their parents were wealthy, and were able to hire none other than Clarence Darrow to defend them. Darrow, instead of trying to defend their innocence, used the opportunity to rail against capital punishment, saving their lives instead of their reputations.
 * The fact that they were Jews also played into the sensationalism of the media coverage of the time. Although apparently they were kinda dicks about their identity: Link.
 * A teenage girl in Bosnia was arrested after the police found a video of her throwing six puppies down the river to drown. And, in the video, she showed no sign of remorse whatsoever. The video is... horrifying and depressing to say the least.
 * Email hoaxes like spunkball. The urban legend is that teenagers, motivated by the hell of it or peer pressure, create incendiary grenades with lighter fluid, paper, and firecrackers. They then drive around and throw these into cars, scoring points for every person they kill or maim. The tellings usually feature An Aesop when one of the spunkballers realizes that he's hurting real people, an epiphany that comes after killing a family member.
 * Similarly, every year there will be some sort of "craze" that's sweeping the nation's teens, usually involving alcohol, sex, or both. Recent ones include vodka tampons, vodka gummy bears, vodka eyeballing, etc. They usually end up being proven not to be as popular as they are portrayed in the media.
 * The Dnepropetrovsk Maniacs. They filmed themselves killing people (one gruesome video being leaked onto the internet) for no reason other than because it was fun. Probably one of the more extreme examples of this trope.
 * Phoebe Prince. The teens at her school tormented her to the point where she killed herself. The unrepentant bullies continued to leave horrible messages on her memorial Facebook page. While police reports noted that Prince was already suicidal long before, this does not excuse what happened to her while attending South Hadley High School, nor does it explain the wretched stories other former and current South Hadley students have told about the social environment, hierarchy, and behaviors endemic in the school. (If anything, the possibility that someone might already have emotional problems should be all the more reason to treat them fairly and respectfully.)
 * Alyssa Bustamente. At 15 years old, she lured Elizabeth Olten (a 9 year-old girl) into the woods. There, she strangled and stabbed Olten to death because she wanted to see what killed a person felt like. Her reactions? "It was ahmazing. As soon as you get over the 'ohmygawd I can't do this' feeling, it's pretty enjoyable."
 * The suicide of Megan Meier, who cruelly had her spirits lifted by a fake online boyfriend, a fabrication headed up by a girl and her mom (!) that hated her guts. She was brought down hard when the "boy" started telling her things like "No one likes you, the world would be better off without you." Shortly after receiving that message, Megan went upstairs and hung herself. She was three weeks away from turning fourteen. This triggered a Real Life outcry of There Should Be a Law when it became clear that the girl and her mom couldn't be arrested for their cruelty.
 * The British "chavs" are possibly a whole culture based on this trope, since violence and bullying are often glorified.
 * The murders of professors Half and Susan Zantop of Dartmouth College were committed by a pair of teenagers from across the river in Vermont, one of whom was the president of his class.
 * The Red Guards were a political movement started by high school students at the beginning of the Chinese Cultural Revolution, which quickly devolved into a gang of thugs who publicly assaulted or humiliated everyone who was perceived to be an enemy of the Revolution. The movement became co-opted by Mao and manipulated to help him purge his rivals in the Communist Party. Eventually, the Guards got so out of hand that the army itself had to be called in to reestablish order all over the country, and even Mao wouldn’t help them.
 * The murder of Reena Virk in British Columbia.
 * And the murder of Kimberly Proctor which also happened on Vancouver island. The teens who were convicted of the crime were sentenced as adults. which was the harshest sentence the judge could give them.
 * The murder of Shanda Sharer who was tortured and burned to death by four teenage girls.
 * The reputation of teenagers being monsters and the fear of school violence is the basis of zero-tolerance policies in the USA. This means that instances that fall under the heading of these policies are not investigated for anything but to determine whether the infraction itself occurred, which of course it did or it wouldn't be an infraction. The Other Wiki has links to criticisms of said policies in its page on the topic.
 * On a similar note, most of what we think of as morality is learned behavior and even empathy takes observation and interaction with others to develop fully. After they clear that hurdle teenagers still do not have much experience with the full motion of adult human experiences but are exposed to many of them so they are more likely to respond to them in unconventional ways. For example reacting to setbacks or shame with irrational anger. To be fair, many adults never clear that moral development stage either.