"I'm Sherri. She's Terri." (Double balloon)
"You must be nice to them - they could surround you!" - Bart Simpson.
Sherri and Terri are a pair of identical twin students of Springfield Elementary School. Terri is younger than her sister by two seconds. They are in the same class as Bart, by Edna Krabbapel. They are a little bit strange and sometimes they speak in their own language. They will also not hesitate to berate Bart as seen in various episodes. No one knows wether one twin is Terri or Sherri.
- They both play the piccolo in the Springfield Elementary School band.
- In Future-Drama, they are both seen in the prom, apparently both impregnated by Nelson Muntz (and their twin babies - despite being in their wombs - share Nelson's trademark "Ha ha!").
- In The Blue and the Gray, it is revealed that they are two-thirds of conjoined triplets, and that the third triplet is out seeking revenge against Sherri and Terri. It is most likely this fact will not be continued in future episodes.
- Bart appears to have a crush on one of them.
- In "The Daughter Also Rises", Sherri and Terri engage in a version of "three card monte" by switching positions between their chairs at a table and disappearing occasionally below the table. As they continue with this act, Marge comments that it now appears that there are three of them. This could mean that the third triplet does exist and just showed up right there.