- “Isn't it amazing the same day you got a pool is the same day we realized we liked you?”
- “The timing worked out great. Don't you think?”
- “You ruined our undefeated season. You ruined everything, ruiner. ...My sister likes you.”
- 1 Biography
- 2 Non-canon appearances
- 3 Behind the Laughter
- 4 Trivia
- 5 Episode Appearances
- 6 Citations
They are quite bright students (they even have their own twin language commonly known as Cryptophasia) and are often very conniving and mean, even to each other. When it comes to Bart they are quite stuck up, and never miss an opportunity to berate him. Bart appears to have a crush on one of them, but Homer states that Terri is the one that Bart has a crush on. One of the twins stated that her sister had a crush on Bart. It is unknown if this is the truth or if it is just teasing. She also has a "boy crazy" cousin who has a crush on Bart. (Bart feels affection for her and she may also feel affection for him).
When it comes to Lisa Simpson they are just as inconsistent. One minute they will be friends on the schoolyard playing together and the next they will be ganging up on her. More often than not it is the latter, usually not including Lisa because she is too smart or too weird. It is implied that she and Sherri are actually two out of three triplets who were conjoined and it is said the third triplet is trying to kill them, but that can be viewed merely as a throw-away joke by the writers, and should not be regarded as canon.
Principal Skinner apparently considers Terri less smart or talented than Sherri, because in Simpson Tide he announces, "In the event of nuclear war, we can only save our best, and brightest. Therefore, space in the fallout shelter will be reserved for: Lisa Simpson, Martin Prince, our championship kickball team, and Sherri, but not Terri." Both the twins Sherri and Terri have creamish-like pale-yellow skin and dark bright purple hair.
In "Barthood", it is revealed that in the future, Bart enters a relationship with Terri. When he throws a party, he accidentally makes out with Sherri who remarked he kisses just like Terri said. He is shocked and asks, "Wait, you're not Terri?" and awkwardly backs away when Sherri tries to continue the encounter. It is unknown what became of this relationship. 
Nelson Muntz simultaneously dated and impregnated both Terri and her sister, who bore him four children (two sets of twins, naturally) shortly before Nelson's high school graduation. It's implied that one of the twins tricked him into thinking he was with the other. He abandoned them during Bart's graduation party, using the same statement his father said to him before abandoning him.
She and her twin are seen at the school assembly behind Bart and Milhouse.
In the second segment BFF R.I.P., after Janey Powell is killed by Ned Flanders' lawn mower she and Terri tells her that losing her best is a life on tragedy, which that she can be their new best friend for life. However, they are killed by a falling tombstone.
Sherri and Terri appear in stages 1 and 2 carrying a burger in a plate for the Simpsons to gain their health.
The Simpsons Game
At the special's climax, Homer and Peter Griffin engage in a lengthy chicken fight, and they knock over some students who are waiting at the bus stop (including familiar characters like Milhouse and Martin). Sherri and Terri are knocked into the street and then hit by Otto's bus, sending the twins flying off-screen.
Behind the Laughter
They have similarities to the Grady Twins (ghost girls) Danny sees in Stanley Kubrick's adaptation The Shining, of Stephen King's The Shining novel of the same name. In a deleted scene of the parody of the Shining called "Treehouse of Horror V" they are ghost twins seen by Bart. They also take on this role in The Simpsons Game were in a game engine elevator they are heard saying "Come Play With Us Simpsons". She is said to be the taller of the two.
- Terri is the one on the right as it was stated by Matt Groening that Sherri is always on the left.
- Both she and Sherri bear some resemblance to the twins Patty and Selma, as both hold an enjoyment for tormenting the males of the Simpson family, but for different reasons, and have a close relative who have a crush on one of the Simpsons.
- It is implied that Sherri and Terri aren't actually twins, but 2/3rd conjoined triplets. This has to be considered just a throwaway joke by the writers, as this 'third triplet' has never been shown or mentioned before.
- Sherri and Terri's last name was finally revealed in the new episode "Yellow Subterfuge", written on Principal Skinner's list of students.
- On November 10, 2019, Al Jean announced via Twitter that Grey DeLisle assumed the roles of Terri, Sherri and Martin Prince, starting with the episode "Marge the Lumberjill", following Russi Taylor's death earlier in the year.
Note: Terri is mainly a background character. Episodes in which she has a speaking role are bolded.
|The Simpsons: Season One|
|"Simpsons Roasting on an Open Fire":||"Bart the Genius":||"Homer's Odyssey":||"There's No Disgrace Like Home":||"Bart the General":|
|"Moaning Lisa":||"The Call of the Simpsons":||"The Telltale Head":||"Life on the Fast Lane":||"Homer's Night Out":|
|"The Crepes of Wrath":||"Krusty Gets Busted":||"Some Enchanted Evening":|
|The Simpsons: Season Four|
|"Kamp Krusty":||"A Streetcar Named Marge":||"Homer the Heretic":||"Lisa the Beauty Queen":||"Treehouse of Horror III":|
|"Itchy & Scratchy: The Movie":||"Marge Gets a Job":||"New Kid on the Block":||"Mr. Plow":||"Lisa's First Word":|
|"Homer's Triple Bypass":||"Marge vs. the Monorail":||"Selma's Choice":||"Brother from the Same Planet":||"I Love Lisa":|
|"Duffless":||"Last Exit to Springfield":||"So It's Come to This: A Simpsons Clip Show":||"The Front":||"Whacking Day":|
|"Marge in Chains":||"Krusty Gets Kancelled":|
|The Simpsons: Season Five|
|"Homer's Barbershop Quartet":||"Cape Feare":||"Homer Goes to College":||"Rosebud":||"Treehouse of Horror IV":|
|"Marge on the Lam":||"Bart's Inner Child":||"Boy-Scoutz 'n the Hood":||"The Last Temptation of Homer":||"$pringfield (Or, How I Learned to Stop Worrying and Love Legalized Gambling)":|
|"Homer the Vigilante":||"Bart Gets Famous":||"Homer and Apu":||"Lisa vs. Malibu Stacy":||"Deep Space Homer":|
|"Homer Loves Flanders":||"Bart Gets an Elephant":||"Burns' Heir":||"Sweet Seymour Skinner's Baadasssss Song":||"The Boy Who Knew Too Much":|
|"Lady Bouvier's Lover":||"Secrets of a Successful Marriage":|
|The Simpsons: Season Six|
|"Bart of Darkness":||"Lisa's Rival":||"Another Simpsons Clip Show":||"Itchy & Scratchy Land":||"Sideshow Bob Roberts":|
|"Treehouse of Horror V":||"Bart's Girlfriend":||"Lisa on Ice":||"Homer Badman":||"Grampa vs. Sexual Inadequacy":|
|"Fear of Flying":||"Homer the Great":||"And Maggie Makes Three":||"Bart's Comet":||"Homie the Clown":|
|"Bart vs. Australia":||"Homer vs. Patty and Selma":||"A Star is Burns":||"Lisa's Wedding":||"Two Dozen and One Greyhounds":|
|"The PTA Disbands":||"'Round Springfield":||"The Springfield Connection":||"Lemon of Troy":||"Who Shot Mr. Burns? (Part One)":|