Mr. Garrison

In the ninth-season premiere, "Mr. Garrison's Fancy New Vagina", Garrison comes out as a trans woman and decides to undergo a vaginoplasty and breast augmentation. In the episode "D-Yikes!", it is revealed that she renamed herself Janet. Garrison frequently asserts her femininity, including through misandry and open proclamations of her sexuality.[12]

The transition causes her relationship Mr. Slave to end, as the latter had not been consulted before the operation. Garrison also realizes that there have been no menstrual periods after the operation, leading her to believe that she is pregnant. Garrison attempts to abort before she is told that her procedure does not result in the creation of reproductive organs. In the episode "Follow That Egg!", she attempts to prevent same-sex marriage from becoming legal after finding out that Mr. Slave is engaged to Big Gay Al.

In the episode "Go God Go", Garrison is ordered by the school district to teach evolution. Due to her personal aversion to the concept, she deliberately underperforms and is subsequently replaced by Richard Dawkins. Dawkins is gradually attracted to Garrison, and they begin dating. Dawkins converts Garrison to atheism, and they subsequently decide to eradicate all religion from the world, leading to a future where the global populace embraces atheism and ignores logic, causing wars about the answer to "the Great Question". In the following episode, "Go God Go XII", Eric Cartman, having been cryonically frozen 500 years earlier, contacts Garrison's home from the future. Dawkins answers the phone and learns from Cartman about Garrison's previous life. Repulsed, Dawkins hastily ends his relationship with Garrison. It is revealed that Garrison was the motivation that convinced Dawkins to teach atheism to the world, and as their relationship ended, the future changed once more.

In the episode "D-Yikes", Mrs. Garrison starts to have lesbian relationships. After an unnamed boyfriend abandons her, Garrison meets Allison, a lesbian who becomes quickly attracted to the former. Unaware of Allison's sexual orientation or growing affection, Garrison unwittingly joins her at a lesbian bar. After Garrison learns the truth, she is initially shocked but quickly returns Allison's feelings, and the two begin to date. As a result, Garrison begins openly identifying as a lesbian.

In the episode "Eek, a Penis!", Garrison becomes disillusioned with living as a woman and wants to detransition. After hearing about genetic engineering being used to grow human body parts on mice, she pays for a procedure to grow a penis on a mouse. After Garrison spends most of the episode chasing the runaway mouse, it returns to Garrison and the sex change operation proves successful.[13]

After his detransition, Garrison's behavior was shown to be less eccentric than before, with significantly fewer acts of deviant sexual behavior, outrageous outbursts, racism, or psychotic episodes.

Garrison as president of the United States

During the nineteenth season, following Principal Victoria's replacement with PC Principal, Garrison becomes frustrated with a recent influx of illegal Canadian immigrants. He begins denigrating the immigrants and is consequently dismissed from his teaching job. He begins a political campaign on promises to get rid of the immigrants and build a wall, parodying the Donald Trump's then-current presidential campaign. After discovering Canada has already built a wall, Garrison goes over Niagara Falls to Canada and rapes the Canadian President—a caricature of Trump—to death. Convinced that his policies work, Garrison continues his campaign, with Caitlyn Jenner as his running mate. The episode "Sponsored Content" features Principal Victoria convincing Garrison to return to South Park.

Parker and Stone had expected the Trump's campaign to end before the 2016 election. They opined that a direct portrayal of Trump would be dated if the campaign ended quickly, and felt it would be more appropriate to use one of their characters in his role, having already decided Garrison would come into conflict with the new principal.[14]

In following seasons, Garrison receives the Republican Party nomination and continues his campaign. He realizes that he will be incapable of actually performing his duties as the president if he is elected, and tries to sabotage his own campaign, even outright telling people to vote for Hillary Clinton instead of hie. While his attempts are initially unsuccessful, he eventually manages to lower his poll numbers by making inflammatory comments about women. As he attempts to tell his supporters that the election is rigged against him, they realize that he had never intended to actually make it as far as he did and furiously pursue him. Seeking refuge in a support group run by Randy Marsh, Garrison learns that people want him for president because J. J. Abrams they were brainwashed into liking Star Wars: The Force Awakens using the sentient Member Berries. After failing to destroy the Member Berries, Garrison makes a speech urging Americans to vote for Clinton in protest of the new film.

Despite his efforts, Garrison is elected president and brainwashed by Jenner, who herself was brainwashed by the Member Berries. Upon winning the election, he uses his newfound power to force people with whom he has had altercations to perform fellatio on him. Garrison plays a role in the season's conclusion by helping to defeat the season's other antagonists while remaining in power.

Parker and Stone expected Clinton to win the election, and revealed that they waited for the election to end to focus on other storylines, intending for a humbled Garrison to return to teaching. Garrison was also intended to play a role in resolving the conflict between the male and female students at the school classroom that had developed over the course of the season, taking responsibility for causing their behavior. Following Trump's win, Parker and Stone were consequently forced to rewrite the season's final episodes, and felt that they could not resolve some of the season's storylines in a satisfying way as a result.[15]

The twenty-first season sees a desperate Garrison returning to South Park after launching a nuclear strike against Canada in "Super Hard PCness". Garrison was absent in all but one episode of the following season, appearing in a cameo in the season finale, "Bike Parade".[16]

Garrison reappears in "The Pandemic Special" as an antagonist who wants to prolong the COVID-19 pandemic, as the virus is also killing Mexicans. At the end of the episode, the pangolin being researched in development for a vaccine is killed by Garrison with a flamethrower, alongside the scientist holding the pangolin. In "South ParQ Vaccination Special", Garrison returns to South Park after losing the 2020 election to return to teaching, but is opposed by everyone except the QAnon-adhering White family. Garrison pleads to the elites, who are toying with he and Bob White, to return his life to normal; he later regains the townspeople's respect after securing COVID-19 vaccines for everyone with the elites' help.

In the twenty-fifth season, Mr. Garrison started dating a man named Rick in the episode "Pajama Day". Garrison's relationship with Rick is tested in "Spring Break", the twenty-sixth season finale, wherein Garrison is pressured by his supporters to run for president again in 2024. Garrison is forced to choose between his relationship with Rick and personal gain, ultimately choosing the former. Garrison returns to Rick, and the two reconcile.

Garrison did not have a known given name until the episode "Cherokee Hair Tampons". In that episode, his full name is Ethan P. Garrison. In "The Entity", his given name is changed to Herbert. During Garrison's presidency, he is generally not referred to by name at all, with characters only referring to him as "The President".

Mr. Hat (left) and Mr. Twig

Mr. Hat initially appeared to be simply a puppet used by Mr. Garrison as a teaching aid. However, it was soon apparent that Mr. Hat was able to perform activities that would not have been possible if he were merely a puppet. It is not entirely clear how much autonomy Mr. Hat and Mr. Garrison have from each other. In the episode "Chef Aid", Mr. Hat is able to drive a car through a prison wall to rescue Mr. Garrison and Chef, to which Chef remarks, "How the hell did he reach the gas pedal?".

Further evidence of Hat's autonomy includes that Mr. Hat has been able to move his eyes and blink towards Mr. Garrison and Brett Favre, and that in "Worldwide Recorder Concert", where Mr. Hat beats up Mr. Mackey, but also in the South Park video game, where Mr. Hat owns and runs a robot factory by himself, or in South Park: Bigger, Longer & Uncut, when Satan picks up Mr. Hat as a companion to replace Saddam Hussein. Satan speaks Mr. Hat's lines in a voice very similar to Mr. Garrison's.

Mr. Hat is also a racist, as seen in "Chef Goes Nanners", where he is a member of the South Park branch of the Ku Klux Klan. Mr. Hat argues with Mr. Garrison and seemingly disappears to attend a meeting without him. Mr. Hat also appears to be somewhat psychotic. In "Weight Gain 4000", furious at Kathie Lee Gifford for a talent show he and Mr. Garrison had lost years ago, Mr. Hat convinces Mr. Garrison to kill her, which he attempts to do. Again, whether this indicates that Mr. Hat is independent or if Mr. Garrison's own psychosis is simply projected to his puppet is impossible to say.

In a fictional crossover psychotherapy session with Dr. Katz (from another Comedy Central series) in "Summer Sucks", Katz suggests that Mr. Hat was a personification of Mr. Garrison's "gay side". Garrison rejected this, and Katz was never able to counterpoint because he was killed shortly afterward by a gigantic novelty firework. Despite this suggestion, Mr. Garrison retained use of Mr. Hat even after coming out as gay, during the period when both were seen to be teaching kindergarten. Mr. Hat is permanently abandoned in favor of Mr. Slave once Mr. Garrison begins teaching fourth grade.

Parker and Stone have said that the removal of Mr. Hat was symbolic of the show abandoning its original style as a surreal comedy in favor of its current format of satirizing real-life issues and events. Mr. Hat was not seen again until the climax of the episode "200", when Eric Cartman demands to speak with him, at which point Mr. Garrison produces Mr. Hat from a dresser drawer, and despite his initial reluctance, Garrison again seems to illustrate an inability to control Mr. Hat, and again addresses him separately. At the conclusion of the storyline, Mr. Hat is again discarded, subsequently appearing briefly in the game South Park: The Stick of Truth[17] and the 2021 special South ParQ Vaccination Special.[18]

Mr. Garrison temporarily replaced Mr. Hat with Mr. Twig (starting in the episode "Summer Sucks"), who consisted of a twig wearing a purple shirt with a pink triangle symbol. His voice was identical to Mr. Hat's until his final scene in "Chef Aid", where he spoke with a French accent. Mr. Twig was not well received by the children in Garrison's third grade class, who repeatedly called for the return of Mr. Hat and suggesting Mr. Twig would be better used as a coat rack, to which Garrison took much offense. Eventually, Mr. Hat returns in "Chef Aid", heralding the fact by some psychopathic attacks on Mr. Twig. Though Garrison constantly assured himself that Mr. Twig was a better choice than Mr. Hat, he came to terms with his attachment to Mr. Hat at the end of the episode upon being broken out of jail by him. Garrison got back with Mr. Hat after Mr. Twig advised him to follow his heart.