The Simpsons began as Matt Groening's dream to satirize American life and culture. As a result, many of the show's characters are incredibly sketchy characters, representing the corrupt side of American empire. This is exemplified in the main protagonist of the show, Homer Simpson, who is an uncultured, ignorant and emotionally stagnant man, who still manages to succeed and have a great life in the United States.
The show criticizes how American culture glamorizes and rewards negative qualities like ignorance, apathy, selfishness, economic greed and arrested development. Its satirical nature would spurn deeper satires of American life in the 1990s and 2000s, with TV sitcoms like South Park and Arrested Development.
Troy McClure
"Hi! I'm Troy McClure! You may remember me from such education films as, Two Minus Three Equals Negative Fun and Firecrackers: The Silent Killer."
Troy McClure is a satire of Hollywood actors who go into acting only for the fame and wealth. The washed-up actor has no job that he'll turn down. From starring in straight-to-VHS educational movies, to hosting mindless TV show like, I Can't Believe They Invented It, McClure uses his name brand to promote anything and everything.
Behind his permanent fake smile, however, is a dark secret that ruined his career. In a parody of big Hollywood names whose careers were also ruined by their hidden secrets, it is revealed that Troy has an extreme love of fish beyond what is considered normal.
Lionel Hutz
Lionel Hutz is Springfield's resident lawyer for its average working class citizens, who cannot afford a real lawyer. When Mayor Quimby's nephew is arrested for beating up a French waiter at Quimby's fancy party, Hutz is hired by the French waiter as his prosecutor. Hutz closes his opening statement, by telling the judge, "I rest my case." To cover his ignorance, he changes this to "case closed". It is pretty clear that Lionel Hutz never went to law school. More so, he cheats his clients, uses their desperation against them, and he gets drunk in court during hearings.
The Simpsons would finally come to their senses when Marge, after losing another case in the hands of Hutz, says that they really need to stop hiring him.
Fat Tony
It has never been clear why an average working class town in the middle of nowhere is attractive as a base for an Italian Mafia gang. Fat Tony is a fun parody of the Italian mafioso as represented in American media. Of course, he is nothing like the real mafia bosses, as nobody in Springfield is scared of him, and he neither murders nor delimbs people.
Nonetheless, Fat Tony is the one bringing in drugs into the town. In many episodes, he is seen as the gateway to all illicit substances in Springfield. To make enough money in such a small town, it can be assumed that either most of Springfield abuses drugs, or Fat Tony uses Springfield as a base of operations for neighboring states.
Ned Flanders
Another satire of American life, Ned Flanders portrays hyper-religiosity and human repression. Ned blocks all the channels on his TV apart from the religious ones, he calls his pastor about his sins multiple times a day, and he forgives Homer no matter how much Homer hurts him or steals from him.
However, Ned is shown to follow the Christian way of life for human praise. When Marge is accused of stealing from The Kiwk-E-Mart, her friends, The Flanders, to whom she has always been very kind, reject her. With Ned's permission, Maude spies on Marge when she uses their toilet, to make sure that the alleged thief does not steal their bathroom supplies.
In Tree House Of Horror XVIII, Ned Flanders appears as the Devil, satirizing the evil hidden in Ned that he represses.
Principal Skinner
Principal Skinner is another repressed Springfield resident whose repression has made him lose a lot in life, resulting in loneliness and unhappiness. Through characters like Skinner and Flanders, The Simpsons criticizes America's puritanical culture that ultimately result in unhappiness and/or mentally unhealthy behavior.
In the case of Seymour Skinner, Skinner operates as a free thought agent against his students. Rather than teach them to think, he installs "Independent Thought" alarms under every teachers' desk in the school to alert him when a student is not being brainwashed by the curriculum. An army veteran, Seymour leads his students like an army general would: he destroys their individuality and creativity to create mindless drones for the benefit of a propaganda-driven nation.
Krusty The Clown
Krusty The Clown is one of The Simpsons' most famous dodgy characters. The man who has faked his death, squandered all his fortune and disappointed Bart numerous times is not exactly known for being a stellar citizen of Springfield. Despite his past, Krusty is given chance after chance by citizens of Springfield, and by Hollywood. His character represents America's obsession with fame, and unrepentant redemption. That is, Krusty always promises to change and be better, but this never comes to fruition.
It is revealed in one episode that Krusty fathered a child that he refuses to acknowledge.
Dr. Nick Riviera
"Hi, everybody!"
Dr Nick is loved by everyone in Springfield - apart from those he's horribly mutilated or killed. The antithesis to an accomplished and trustworthy doctor like Dr. Hibbert, Dr. Nick will perform any operation for $129.95. When Dr. Hibbert informs Homer that triple heart bypass surgery will cost upwards of $40,000, the family is forced to use Dr. Nick's service. During the surgery, Dr. Nick uses a melody to remember heart parts and where to cut. Indeed, Lisa has to teach him where to make the coronary incision.
Dr. Nick is actually a sad portrayal of working-class neo-liberal American life, where the average citizen cannot afford life-saving hospital care when they need it.
Officer Wiggum
Officer Wiggum, in true US police stereotype, is a corrupt lazy officer who actually looks like a pig. To protect and serve might be inscribed on his badge, but Wiggum dismisses people's frantic calls to his office about criminal activity so that he can stay in his office eating donuts and junk food all day.
Despite joining the police force with the same desire to protect and serve, Marge, a really good cop, quits soon after when she realizes how corrupt Wiggum and his district are.
Mayor Quimby
Mayor Quimby and Officer Wiggum are living metaphors of the insidiously corrupt nature of American law and order. Like Wiggum, Quimby is exceedingly corrupt. He does not care about his position, and has no morals, flip-flopping on issues according to whichever stance would win him the most votes in the next election. So amoral is he, that he spends public funds on his personal hedonistic lifestyle, including cheating on his wife constantly. A satire notwithstanding, Quimby's story is eerily similar to that of many lead politicians in Americas political sphere.
Mr. Burns
Mr. Burns reputation for evil is, at this point, ubiquitous among TV fans. Flashbacks to Burns' life reveals that his grandfather taught him the best ways to oppress the poor. To cut the costs of his factory, Mr. Burns dumps nuclear toxic waste inside trees at the dead of night. Not only that, he dumps nuclear waste in Springfield's rivers. Even worse, he never repairs damages in his nuclear plant, essentially leaving his employees to work in very unsafe conditions.
When his employees finally strike, Mr. Burns laments that he is no longer allowed to murder union workers and beat up union members like in the old days.