A group of four foul-mouthed third-then fourth grade boys who reside in a Crapsack World in the state of Colorado known as South Park. Along their misadventures in the town, they often find themselves in various sticky situations and exposing themselves to things kids their age shouldn't be. They are based on the suspicious belief parents hold about how their children behave without adult supervision and are quite possibly Western Animation's most infamous example of Kids Are Cruel, but they nevertheless come out clean and learn An Aesop at the end of the day.
- Adorably Precocious Child: All four of them are prone to possessing the knowledge of adults or teenagers in the recent seasons and voicing their opinions on the recent news, but still have that childish side to them nonetheless.
- Aesop Amnesia: Due to Status Quo Is God being played straight prior to Season 18, the boys forget whatever lesson they previously learned and are back to their rebellious ways by the next week.
- Anti-Hero: All four boys have different shades of anti-heroism.
- Stan usually varies between a Pragmatic Hero to a Knight In Sour Armor.
- Kyle varies between Pragmatic Hero to Unscrupulous Hero depending on how much he's fueled by his hatred towards Cartman
- Cartman is usually a Nominal Hero, though later seasons portray him more as a Villain Protagonist
- Kenny could be seen as the most heroic of the four boys, but his numerous deaths have led him to become a Knight In Sour Armor and is definitely The Hedonist.
- All of the Other Reindeer: At the start of the series, they were relatively well-liked by their classmates, and were perfectly willing to bully their less popular peers. However, as the show went on, a combination of Character Development and Characterization Marches On led their social status to become much more fragile. According to Craig, all of the other kids think they're assholes. Even if he was exaggerating, it still isn't all that unusual for their popularity to dip beneath Butters. Though their popularity is constantly in flux, being despised by their peers in some episodes, and having sleepovers with them in others. Generally speaking, Stan, Kyle and Kenny are usually in good standing with the other kids, although they have a rivalry now with Craig, Clyde and Token who have their own little group. The lightning rod of the disdain is, of course, Eric Cartman, who is the most hated kid in school by far. As much as the other kids pick on Butters, their hatred of Cartman is exponentially greater.
- Characterization Marches On: In the older seasons, they were all average foul-mouthed schoolyard bullies who targeted the less fortunate and engaged in rebellious behavior for the fun of it. Fast-forward to Season 12, and they've become more opinionated and brutally honest in regards to the world's imperfections. Pretty much reaches its epitome by Season 18, where the show has developed a story arc.
- Color-Coded Characters:
- Cartman - Red, blue, and yellow
- Stan - Brown, blue, and red
- Kyle - Orange and green
- Kenny - Orange
- Beware the Nice Ones: Excluding Cartman, they're generally well-meaning, if occasionally troublesome. But if you get on their bad side, you will regret it.
- Blonde, Brunette, Redhead: Kenny's the Blonde, Stan and Cartman are the Brunettes, and Kyle's the Redhead.
- Butt-Monkey: All four of them have had their own moments of suffering misfortunes:
- Cartman was perpetually on the receiving end of obesity jokes much to his chagrin. In addition, the very first episode is literally about Cartman having been anal-probed by aliens and farting flames before his eventual abduction. While he's still prone to bad luck in the recent seasons, he's become more deserving of it due to his tendency to commit Moral Event Horizon acts.
- Stan was regularly assaulted and bullied by his sister Shelley, which has wholely been phased out in the recent years.
- Kyle is a frequent target for Cartman's anti-Semitic jokes, slur-spewing, and humiliations like having to stick his finger up his ass to activate an anal probe or be forced to literally suck his balls.
- Kenny was the resident butt-monkey and chew toy in the early years, sharing this role with Pip before Butters was introduced a regular character. His abject poverty was a frequent target for Cartman's ridicule. What's more, he had the infamous tendency to die in every episode only to be revived by the following week.
- Childhood Friends: They have known each other since preschool... and even back then, Kyle and Cartman were Vitriolic Best Buds.
- Cute Bruiser: With the exception of Cartman (though even he has his moments), all of them have shown remarkable hand-to-hand combat skills; they effortlessly toss around another group of kids in "Faith Hilling"; Kenny (as Mysterion) beats up an older girl in "The Poor Kid"; and Kyle knocks out Cartman with a single punch in "Doubling Down", among other examples.
- Deadpan Snarker: They all have their moments of witty banter and sarcasm.
- Depending on the Writer: Their intelligence fluctuates by episode. In some they are capable of taking on adult responsibilities and rant about the wrongs in modern-day society, which has become more prominent in the recent seasons, while in others they can't even tell the difference between TV and real life.
- Flanderization: With the exception of Kenny (whose pervertedness has been notably toned down), all three of their traits have become more prevalent as the show continues.
- Stan and Kyle's statuses as the only sane men have increased either due to the adults' incompetence or Cartman's ridiculously cruel and sociopathic actions.
- Speaking of whom, Cartman has become more sociopathic and malicious following the infamous "Scott Tenorman Must Die", also becoming more criminal and manipulative in the process. Compare him in the first four seasons, where he was a naïve bully with a good heart, and you'll notice how drastically he's changed.
- Four-Man Band:
- Four-Temperament Ensemble:
- Stan: Phlegmatic. He's calm, sensitive, easygoing, and even-tempered, rarely losing his cool.
- Cartman: Choleric. He's unsophisticated, loud, domineering, and naïve, but very sociable and wears his sociopathic instability on his sleeves.
- Kyle: Melancholic. He's temperamental, morally-driven and quite the most compassionate and emotional of the group. In earlier seasons, he's occasionally seen as an outcast. Additionally, Cartman's shenanigans often get the best of his mood.
- Kenny: Sanguine. A perverted Dirty Kid who's shown to be light-hearted and hedonistic. Underneath his hood, he's heroically selfless, loyal, and can be surprisingly eloquent.
- Free-Range Children: They're old enough to wander outside without adult supervision.
- Guile Hero: In their Crapsack World, they tend to save the day by being smarter and having more common sense than the adults (though Cartman tends to border more into Manipulative Bastard territory).
- Heterosexual Life-Partners: They're Vitriolic Best Buds, but they're always on each other's side in the end and are not embarrassed to exhibit their emotional sensitivity should something bad happen to one another. Even Cartman still manages to gain some acceptance from the other three every now and then.
- Karma Houdini: Often due to the fact that the adults in town are either useless or just as immature and irresponsible, the boys tend to receive zero comeuppance for their Troubling Unchildlike Behavior.
- Kids Are Cruel: They are based on the suspicious belief parents hold about how their children would behave without the presence of an authority figure. Technically speaking, the Boys are notorious for using foul language, disrespecting authority, watching vulgar media, and bullying the less fortunate. This becomes Downplayed around Season 12, where the show becomes more up-to-date in regards to Real Life events and the Boys in turn become more culturally adept.
- Never Bareheaded: Except for Cartman (who is frequently seen without his hat) they almost never take off their hats. In Kyle's case, it's to hide a really embarrassing Jewfro. Kenny never took off his hood, so no-one knew what he looked like until he finally took it off in the movie.
- Nice Hat: All of the main four characters wear hats (though one would be hard pressed to consider them particularly "nice"). The episode, "Follow That Egg", however, has the following exchange:Kyle: Do you really think my hat is stupid?Stan: As a matter of fact... I think it is the nicest hat I have ever known.
- Sir Swears-a-Lot: Notorious for having the mouths of sailors.
- Took a Level in Cynic: Around Season 12, the Boys become more culturally adept in turn of the show becoming more up-to-date about Real Life events, and start to abandon their childish ways in favor of a social justice warrior knowledge.
- Took a Level in Jerkass: Stan and Kyle in Season 6 toward Kennys replacements (Butters, and later Tweek). Its no surprise that Cartman would manipulate others, but its unusally cruel for them.
- Took a Level in Kindness: They become notably less hostile to social outcasts like Butters and Scott Malkinson by Season 12, even allowing them into their extended group at times.
- Troubling Unchildlike Behavior: Since Adults Are Useless, their main schtick is using foul language, outfoxing authority, watching vulgar media, and even engaging in criminality at times.
- True Companions: Lampshaded in the South Park episode "The Biggest Douche in the Universe", when Chef tells Stan and Kyle that Cartman is their friend whether they like him or not. This trope becomes more apparent in later seasons, once their Weirdness Magnet status has begun to wear old; the boys fall victim to All of the Other Reindeer more often, making it evident that, while their classmates may tolerate them, they don't really have any friends outside of one another. As much as they would hate to admit it, they're a textbook example of this trope.
- Vitriolic Best Buds: Their most defining trait is using aggression and teasing to portray their friendship. They're also not above outcasting one another out of their group for a bit, only to come back together in the end.
- Weirdness Magnet: Lampshaded in South Park "Pandemic 2 — The Startling," when Craig gets sucked into the boys' adventure because they were using his birthday money for their scheme.Craig: That's a shock. I decided to follow you guys, and now I'm in the Land of the Giant Lost World.
Stan: Craig, it isn't our fault! You make it sound like we always wanna be in situations like this but we don't have any choice!
Kyle: Yeah! Stuff just happens!
Craig: "Stuff just happens."
Kyle: That's right!
Craig: You just wind up being sent by the government to take down the city of Lima only to wind up in the Land of the Giant Lost World.
Cartman: That's right.
Craig: You know what stuff happens to most kids? They fall off their bikes. They get in fights with their parents. They get swindled out of their birthday money.
- Wise Beyond Their Years: They're all pretty perceptive for their age, albeit in different ways.
- With Friends Like These...: Cartman versus everyone else. He takes this further than most cases of this trope, as Cartman has almost no redeeming qualities. Also uncommon for the trope, the other characters will flat out tell Cartman that he is a monster. Not only do they state he's a horrible person but that they all hate him and the only reason he was ever with anyone was that they thought he was just always following them or that he was with someone else. After realizing this they decided to ignore him completely. The creators stated that Cartman's relationship to the others is based on their assumption that everyone has one friend that they don't really like. It's worth noting that in the early seasons, Cartman was just a Fat Idiot - his supervillainish disposition evolved over time.