Aria dragons are a brightly-colored and sprightly breed, perhaps most adored for their lyric calls. Their song-like melodies fill the areas they inhabit; their coos resemble those of birds, only more elegant and refined. They have fairly strong magical capabilities, but tend to reserve these strengths for last-minute defense, choosing to live their lives in simple peace. Arias, sticking to the tropics, typically live quite far from human settlements, giving rise to the previously held belief that they had gone extinct.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Princess Bubblegum is the ruler of the Candy Kingdom in the Land of Ooo. She is very accomplished in many fields of math and science and invents many useful potions and contraptions. She has difficulty staying safe as The Ice King always tries to kidnap her and force her to marry him, but Finn the Human is always ready to save her. Finn is in love with PB, but her feelings towards him are unclear. Her pet is Lady Reignicorn.