I an animated show (usually mature shows), there is usually one episode where a character does something that makes him/her the most hated person in town:
THE SIMPSONS
Bart: When he gets framed for stealing the church's collection money.
Homer: When everyone thinks he tried to rape a babysitter. Though cruel, the "sweet can" scene always cracks me up!
Bart: When he fumbled an easy fly-ball and cost Springfield the Little League Championship. By far the worst example.
Lisa: When she preaches that the story of Jebediah Springfield was a lie!
Grampa: When his senility costs Springfield the chance of having an NFL team of its own.
Mr. Burns: Everyone hates him! Seen the most in "Who Shot Mr. Burns" and "The Fool Monty".
The Simpson family: "Miracle on Evergreen Terrace" and "Bart-Mangled Banner".
Kent Brockman: When news got out that he said a horrible swear on live TV.
Lisa: The trouble of being an honor student.
KING OF THE HILL
Hank: When he opened the city dam's flood gates (it was about to break from water pressure) and flooded Arlen.
Hank: When it was thought that he was racist (due to his dog's seemingly racist behavior).
FAMILY GUY
The family: When Stewie threw up the host and communion wine and was thought to be possessed. The Griffin house was encircled with people.
Brian: When word got out that he was an athiest. Frakkin' CARS were thrown through the window.
Lois: When word got out that she starred in a porno film.
Meg: When she took the blame from Peter that she drove into a satelite and knocked off Quahog's TV service.
Peter: When Meg told everyone the truth!
Meg: On a daily basis.
SOUTH PARK
Stan: When he said voting was no big deal. This is THE most heinous crime in South Park.
Kyle: He and other gingers were targeted by everyone (thanks to you-know-who!).
Randy: When he unintentionally said the "N"-word on television.
Randy: When his theory of always passing gas caused massive global warming.
Cartman: EVERYONE hates him! And for good reason!
Any more?
THE SIMPSONS
Bart: When he gets framed for stealing the church's collection money.
Homer: When everyone thinks he tried to rape a babysitter. Though cruel, the "sweet can" scene always cracks me up!
Bart: When he fumbled an easy fly-ball and cost Springfield the Little League Championship. By far the worst example.
Lisa: When she preaches that the story of Jebediah Springfield was a lie!
Grampa: When his senility costs Springfield the chance of having an NFL team of its own.
Mr. Burns: Everyone hates him! Seen the most in "Who Shot Mr. Burns" and "The Fool Monty".
The Simpson family: "Miracle on Evergreen Terrace" and "Bart-Mangled Banner".
Kent Brockman: When news got out that he said a horrible swear on live TV.
Lisa: The trouble of being an honor student.
KING OF THE HILL
Hank: When he opened the city dam's flood gates (it was about to break from water pressure) and flooded Arlen.
Hank: When it was thought that he was racist (due to his dog's seemingly racist behavior).
FAMILY GUY
The family: When Stewie threw up the host and communion wine and was thought to be possessed. The Griffin house was encircled with people.
Brian: When word got out that he was an athiest. Frakkin' CARS were thrown through the window.
Lois: When word got out that she starred in a porno film.
Meg: When she took the blame from Peter that she drove into a satelite and knocked off Quahog's TV service.
Peter: When Meg told everyone the truth!
Meg: On a daily basis.
SOUTH PARK
Stan: When he said voting was no big deal. This is THE most heinous crime in South Park.
Kyle: He and other gingers were targeted by everyone (thanks to you-know-who!).
Randy: When he unintentionally said the "N"-word on television.
Randy: When his theory of always passing gas caused massive global warming.
Cartman: EVERYONE hates him! And for good reason!
Any more?