She and Shermy appear to live in Marceline's now-abandoned house, which is a reference to how Finn and Jake lived in the Tree Fort, which originally belonged to Marceline. She is a descendant of Jake and Lady Rainicorn.
Beth is a large and rounded pup. She is a tone of yellow similar to Jake and has similar eyes, ears, and snout. Additionally, she has a horn on her head, like her ancestor Lady Rainicorn, as well as having a large belly button.
In a failed attempt to capture the Prize Ball Guardian, Shermy found Finn's lost mechanical arm. To learn its origins, Beth suggests visiting the fabled "King of Ooo," who in their time is a lonely BMO, living in a house on the top of Mount Cragdor, surrounded by relics of his past and thought to be nothing but a legend. When Beth shows BMO the arm, he finally consents to tell her and Shermy about the Gum War, the battle against GOLB and the final fate of the people of Finn and Jake's era.
After their visit with the "King of Ooo," Shermy then remembers to have seen the Fern Tree (previously shown in "Lemonhope Part 2" and "Graybles 1000+") in his travels around Ooo. The two arrive at the tree and climb all the way to its top, finding the restored Finn Sword. After finding the sword, she instructs Shermy to lift up the sword, leading him to mimic Finn's iconic pose seen in the show's opening sequence, as Beth assumes the pose made by Jake.
Beth has the ability to teleport objects from other locations through her belly button, as well as store objects inside of her belly button for transportation purposes.
- Beth, numbered as Pup #38,000, is a descendant of Jake and Lady Rainicorn.
- Her surname "Jakson" is based on the fact that the Pups are Jake's descendants.
- Her middle name, "Burrito," seems to have been inspired by Jake's love of burritos.
- Beth shares part of her name with Beth Tezuka, a character from Bravest Warriors another series created by Pendleton Ward.