The Poor Kid/Trivia

Trivia

 * Matt Stone and Trey Parker officially confirmed the name of Kenny's sister to be "Karen", after years of fans referring to her by that name.
 * Kevin and Karen McCormick have undergone a slight redesign for this episode.
 * This episode showcases Butters' computer knowledge.
 * Kenny is referred to as "Kenneth" by Mr. Weatherhead, which is his real first name.
 * It is revealed that Cartman is the second poorest kid at South Park Elementary (or at least in the 4th grade).
 * For Cartman to be the poorest kid in school while Kenny is away, Tammy Warner, who was even poorer than Kenny, must have either died of syphilis or moved away from South Park.
 * Kenny, as Mysterion, shows his fighting ability, and was able to take out a larger girl with extreme ease, as well as kicking her in the head whilst jumping.
 * It is revealed that Liane Cartman works two jobs, however it isn't revealed what those jobs are.
 * This is the first time Kevin McCormick has spoken since the Season Two episode "Chickenpox", made 13 years prior.
 * We hear Mysterion's signature music from the introduction of "Mysterion Rises" again during his fight with Jessica Pinkerton.
 * Jessica Pinkerton should not be in Karen's class. She is around 11-12 years old, when Karen is around 6-7, but she may be in another class and just wants to beat up Karen.

Continuity

 * This is Karen McCormick's second appearance, her first being in "Best Friends Forever" as well as her first speaking role.
 * This is Kevin McCormick's first appearance since the episode "Sexual Healing".
 * Kenny reprises his alter ego, Mysterion, in this episode - however, unlike previous appearances, the episode focuses on both "Kenny" and "Mysterion", rather than just one or the other. This is also the first time Mysterion appears alone without Cartman as The Coon.
 * This episode marks Kenny's first death and appearance as Mysterion since last season's episode "Coon vs. Coon and Friends". This is also his only death in Season Fifteen.
 * This marks the first time people have acknowledged Cartman's peculiar way of pronouncing certain words and names, such as pronouncing "Kyle" as "Kyahl", "Kenny" as "Keeny", and saying "meem" instead of "mom".
 * This is the fifth time Cartman has been in jail; he was previously jailed in "Cartman's Silly Hate Crime 2000", for fighting with Token Black; "Die Hippie, Die", for kidnapping hippies; "Casa Bonita", for kidnapping Butters Stotch (implied but not shown on screen) and "Whale Whores", for destroying a Japanese whaling boat.
 * This is the second time Cartman has had his mom arrested; he has previously done so in "The Wacky Molestation Adventure".
 * This is the third time Kenny's parents have been seen arrested. The first time was in the episode "The Wacky Molestation Adventure", when they were falsely arrested under the belief that they were molesting their kids, and the second time was in the "Mysterion Rises", when it was revealed that they were arrested at a Cthulhu Cult Meeting ten years ago.
 * Kevin McCormick speaks with a slow slur and can be seen on the short school bus in earlier episodes, indicating that he is either mentally disabled or regularly intoxicated.
 * The meth lab at the McCormick residence was mentioned in "Lil' Crime Stoppers", when the mob boss mentions that they will have to have the McCormick's start making their meth again.

References to Popular Culture

 * Mysterion paraphrases Yoda's famous quote, "Do or do not, there is no try" from the movie The Empire Strikes Back, telling his sister, "Do not try Karen, do.".
 * The foster family is an exaggerated caricature of agnosticism, mocking the ambivalence of agnostic beliefs. It is also a parody of the narrative cliché of highly religious abusive foster parents.
 * The Weatherhead foster family may be based on Leslie Weatherhead (1893-1976).
 * Jokes were repeatedly made in reference to the Penn State scandal.
 * This is the first episode to refer to Dr. Pepper by name.
 * A man witnessing the McCormick's arrest is wearing a Diablo II shirt
 * Mr. Adams closely resembles the character Zach Galifianakis played in the movie Due Date. His character Ethan Tremblay/Chase reguraly thought himself to be a comedian and gave his audience signed photographs off himself.

Goofs

 * Tammy Warner is infact, poorer than Kenny.
 * When Jessica is kicked to the ground, she doesn't have a black eye. But when Mysterion pulls her head up, it appears.

Kenny's Death

 * Kenny is unexpectedly killed by a "giant reptilian bird" moments before the end of the episode. His death is a callback to the "Agnostic Code" that his foster parents teach their adoptive children, specifically the part that reads "Then again, there could be a giant reptilian bird in charge of everything".
 * The "Oh my God, they killed Kenny" and "You bastards!" lines are not used, instead Stan simply replies, "What the fuck?".