Terri and Terry Perry

Terri and Terry Perry are two of the three secondary tritagonists in Monsters University, alongside Art. They are yellow four-armed Siamese brothers with horns and orange stripes on their tentacles, and students at Monsters University, as well as members of the Oozma Kappa fraternity. Terri is the smaller and has one horn; Terry has two horns.

Official Bio
"When it comes to Terri and Terry, it’s hard not to ask, “Are two heads really better than one?” These bickering brothers have little in common: Terri with an “i” is a real romantic who’s quick to spot the silver lining in any situation, while older brother Terry with a “y” sports a more cynical outlook on life. If they can stop squabbling long enough to work with their Oozma Kappa brothers—they might be able to put their heads together—literally—and find their place in Monsters University’s Scare Program once and for all."

Trivia

 * Terry is the first new Pixar character that Dave Foley has played since Flik in A Bug's Life.
 * Each control one pair of arms, but only the arms on each side and not across from each other. For example when Terri dances for Mike and Sulley as they move into the OK house only his arms move while Terry's arms remain still with one holding a hot chocolate mug. Another time when they were in the Library, Terri, after witnessing the librarian toss out a student through the skylight, clutches both his brothers arms in fear for a brief moment.
 * Terri and Terry's heads are shaped like the letters at the end of their names, especially judging by the shapes of their horns: "i"'s horn resembes a tittle (the dot above the lowercase i and j) while "y"'s horns resemble the arms of a y and his neck resembles its tail.