Shmipper and Smabble

Shmipper and Smabble are young twins residing in Gravity Falls, who, despite a similar appearance to Dipper and Mabel Pines, illustrate completely opposite personalities.

Season 1
The siblings joyfully play with each other in "Tourist Trapped," moments before Dipper and Mabel crash through the town's welcome sign.

In "The Legend of the Gobblewonker" Shmipper and Smabble spend the Opening Day of Fishing Season with their grandpa, "Pop Pop," and express unconditional affection towards him while Stan watches from afar, clearly envious. As he jeers at the family, Pop Pop reacts angrily, but Shmipper reminds his grandpa that it's possible Stan has no one who loves him.

According to "The Time Traveler's Pig," Smabble visits the grand reopening of the Wax Museum of Mystery in "Headhunters," sitting among the crowd anticipating their promised free pizza.

As Stan recalls his first encounter with Gideon in "The Hand That Rocks the Mabel," the twins cheer for the child psychic's tour bus in his flashback, and later attend his performance at the Tent of Telepathy.

In "Double Dipper," the two attend party held at the Mystery Shack, watching Mabel and Pacifica combat for the title of Party Queen.

During the town's celebration of Pioneer Day, Smabble observes the librarian create candlesticks while Shmipper celebrates Mabel's patriotic speech. Pacifica later kicks Smabble off her maypole team for tripping in "Irrational Treasure."

The twins attend the Mystery Fair in "The Time Traveler's Pig," and Smabble later returns in a flashback when Dipper and Mabel accidentally travel back to the grand reopening of the Wax Museum of Mystery.

In "Summerween," Smabble participates in the local holiday Summerween, trick-or-treating with her friends as a daisy. Upon visiting the Mystery Shack, she is quickly frightened off by Stan alongside with two of the other children.

Shmipper visits the Mystery Shack with the unnamed farmer in "Boss Mabel" during its new management phase.

In "Carpet Diem," Shmipper walks down main street with the woman in orange, unaware of Soos' possession of Waddles' body.

Smabble attends the Sev'ral Timez concert held at the Gravity Falls Civic Center and Buffet in "Boyz Crazy," where she later gets involved in a physical altercation with her friend over the affections of the band.

In "Gideon Rises," Smabble joins the townsfolk in a celebratory visit to the Mystery Shack following Gideon's defeat, where she purchases a shirt.

Shorts
Smabble watches Mabel perform "Mabel and Bear-O" in the short "Tooth," and, like the other children, grows hysterically terrified of Bear-O following the song's conclusion.

Season 2
The twins both spend the day golfing with their Pop Pop at the Ye Royal Discount Putt Hutt in "The Golf War," however they're forced to leave due to the weather.

Smabble is among the crowd applauding the performance of Hoo-Ha's Jamboree in "Soos and the Real Girl," and willingly tips the animatronic "Willy Badger" after his show.

In "Society of the Blind Eye," Shmipper's photo is on Dipper's "Mystery Board," as he is deemed to be one of the number of "suspicious townsfolk" within Gravity Falls.

During her role as matchmaker in "The Love God," Mabel categorizes Smabble as "too young" to date Robbie, thus eliminating her as a candidate.

Personality
Shmipper and Smabble seem to be very cheerful, happy-go-lucky, and are usually seen laughing and smiling. They also seem to be very optimistic and kind (notably in "The Legend of the Gobblewonker" when Shmipper said that maybe Grunkle Stan had no one who loves him, after he booed their happy grandkid-grandparent moment).

Appearance
Shmipper and Smabble are siblings who bear a striking resemblance to Dipper and Mabel, and are sometimes mistaken as younger versions of Dipper and Mabel. They both have brown hair, small noses, and freckles on their cheeks. Shmipper has blue eyes and is usually seen wearing a red t-shirt; whereas Smabble has green eyes and is usually seen wearing a pink t-shirt. They are commonly seen smiling and laughing or acting playfully. They are most likely younger than Mabel and Dipper, due to their size and immature demeanor.

Quotes
"Can you pwease tell me mo'e funny stories, Pop Pop?"

- Shmipper adores his grandfather's company.

"Maybe he has no one who wuvs him, Pop Pop."

- Shmipper is sympathetic towards a lonesome Stan.