Kyle has reddish-auburn-ish short curly hair with an auburn copper-brown tint or reflection to it. He wears an orange winter coat with a lime-green collar, a lime-green ushanka hat, matching lime-green winter gloves, army-green cargo pants, and black boots. Kyle has extremely strong beliefs, and when forced to question them, he becomes very upset and has somewhat of a short temper (especially when it comes to Cartman. This is has caused a lot of fights between the two boys). For the most part, Kyle bases his decisions on both his emotions and beliefs; therefore, he is easily coaxed into fights or manipulated by his feelings, an example of this being when Cartman sang a song about his mother being a "bitch" and got everyone to join in, which annoyed Kyle. As a result, this has happened at least twice. Cartman is more than happy to poke fun at Kyle in other ways as well, which has landed him in trouble many times. However, Kyle has been known to abandon his beliefs if there is a lot of money in it for him and self-justify himself despite knowing how wrong he is.

Cartman has brown hair, blue eyes, and wears a bright-red winter coat and bright-yellow winter gloves. He wears a teal-blue winter cap hat similar to Stan's winter hat with a flat yellow puff on top similar to Craig Tucker's hat's flat yellow puff, brown khaki pants, black shoes, and white socks. One thing most notable about his physical appearance is that he is obese, which his friends and peers, mostly Stan, Kyle, and Kenny almost constantly body-shame him for and bully him for. Cartman is described in various terms, in short, he is a funny, vicious, angry, good (sometimes), bad, nice, self-absorbed, immature, destructive, sarcastic, snooty, loud-mouthed, lazy, and hilarious fatass. He is the most foul-mouthed character in the show. He is also a racist bully and stereotypes almost everyone he sees, usually seen bullying Kyle for being Jewish, Kenny for being poor, and Stan for being bisexual. The very dark, usually disturbing undertones to his personality often hint at an extreme mental imbalance. Apart from being portrayed as having a general lack of moral responsibility or social conscience, he also seems to take pleasure from others' misfortune and is generally unable to show empathy. Cartman can, on rare occasions, show compassion towards cats.

Kenny has messy blond hair, blue eyes, and a pale skin tone. For his outfit, he wears an orange parka, orange pants, and black shoes. Kenny is the second kindest, sweetest, and most sensitive and tender member of The Boys after Stan. He is also the smartest of the four main boys after Kyle.