Princess Bubblegum (full name Princess Bonnibel Bubblegum, often called PB and on occasion Peebles and other nicknames) is a main character on the series Adventure Time that first appeared in the Animated Short. She is the benevolent ruler of the Candy Kingdom, and is Finn's former crush. She is also Ice King's most often-targeted princess. Marceline calls her by her first name, Bonnibel. At the end of "Mortal Recoil," she was transformed into a 13-year-old, but returned to her normal biological age of 18 years at the end of "Too Young."
Princess Bonnibel Bubblegum is the beloved ruler of the Candy Kingdom. Though not much is said about her past, there are some allusions to her relatives (e.g. Uncle Gumbald, mentioned in "Susan Strong"). It is implied that Finn has saved Princess Bubblegum many times, though she winds up saving him in the episodes "Dungeon" and "Lady & Peebles." It also seems that she has had previous run-ins with Marceline, the vampire queen. In the past she created Lemongrab (the first one of her experiments gone wrong), then sent him away to live a sheltered life inside his own castle. Princess Bubblegum also performs other science experiments which vary from very successful to catastrophic.
In the second season's two-part finale, "Mortal Folly" and "Mortal Recoil," she sends Finn and Jake on a quest to stop the Lich from killing everyone in Ooo. She gives Finn the Gauntlet of the Hero Billy, as it is the only known weapon that can harm the Lich, and a sweater she made herself. The Ice King captures Princess Bubblegum and chases after Finn and Jake to get their blessing to marry her, but he accidentally drops the princess into a pit of green liquid. She is soon melted into a pile of pink-brown goo and is rushed to the hospital.
It is soon revealed that the spirit of the Lich possessed the princess earlier and eventually warps her into a giant monster that nearly tears apart the Candy Kingdom. Finn enlists the power of Ice King to immobilize her with ice. Unfortunately, the frozen princess topples over and breaks to pieces. The doctors reassemble her but lack all the necessary pieces, reducing her age to 13 (the same age as Finn at the time). According to Adam Muto, her body was composed of only enough reclaimed biomass to be an adolescent, and therefore she turned into one.
As a 13-year-old, Princess Bubblegum is technically younger than the Earl of Lemongrab and he claims his right to the throne until she turns 18 again. Princess Bubblegum is forced to restore herself to her 18-year-old form with the contribution of biomass (candy) from the Candy People and a hug (and kiss) from Finn. After reverting to her proper age and size in "Too Young," she jokingly acts as if the events that happened earlier that same day (while she was 13) actually happened five years ago.  In "Burning Low," Princess Bubblegum revealed that Flame Princess is physically unstable, and she stopped Flame Princess's Elemental Matrix from causing the end of the world: she cut off her oxygen supply by guiding Jake to block the hole that was made, thus defueling Flame Princess (and nearly suffocating her and Finn, who had jumped down after her).
During the events of "Lady & Peebles," Princess Bubblegum defeats Ricardio by beating him up with her bare hands, and she saves the Ice King's life by making him a new heart.
Princess Bubblegum patches up her rocky relationship with Lemongrab in "You Made Me!" by making him a Lemongrab clone, so he will have a friend who truly understands him. At the end of the episode, the princess bids them a fond farewell and they both invite her to visit anytime, indicating that the three of them are on good terms.
Personality and traits
Princess Bubblegum is an extremely intelligent, amiable and nice ruler. She loves (most of) her subjects and has been known to defend them tirelessly when trouble brews. In "Princess Cookie," her dedication to her Kingdom is shown when she visits a Candy Orphanage and spends some time cheering up the children.
Princess Bubblegum has a strong sense of morality and participates in politics outside the Candy Kingdom. She is very noble and intelligent, perhaps the most intelligent being in Candy Kingdom.
Princess Bubblegum is a highly cultured and educated ruler with an undying passion for science. In "Slumber Party Panic," she attempts to revive the dead Candy People, accidentally creating a horde of zombie Candy People instead. In her dedication, she sometimes drives herself to exhaustion with her experiments such as the perfect sandwich in "Five Short Graybles" and the eponymous character in "Goliad."
Though ordinarily sweet and good-natured, Princess Bubblegum shows a malicious aspect of her personality whenever she is crossed, as toward the Duke of Nuts for eating all of the royal pudding and supposedly ruining her appearance. Even with her kind disposition, her moral code is not as strict as Finn's. She sometimes says morbid or inappropriate things, such as when Finn picks up a paralysis poison and she says, "That's paralyzing potion, Finn! Don't touch it, or it'll paralyze you forever!" and then giggles. Many darker things are briefly shown in several episodes such as skeletons cuffed to the walls in hidden chambers as shown in "Ricardio the Heart Guy." Also, in "What Have You Done?," she displays a non-hesitant willingness to torture Ice King.
When she is 13 years old in "Too Young," she exhibits a playful attitude and a willingness to perform pranks with Finn. Just before Princess Bubblegum is returned to her normal age she mentions that she enjoyed temporarily being 13 because she was free from the responsibilities that came with being ruler of the Candy Kingdom and that she could act like a kid again. In Princess Bubblegum's own words, being thirteen was "bloobalooby."
Princess Bubblegum acts noticeably more child-like when she is not in her role as the princess. She dresses and talks more casually when she isn't busy with her work, as seen in "Video Makers" and "What Was Missing." As a princess, she is prim, poised, and straight-laced, but is quite capable of loosening up and dressing/acting like a regular teenager with her friends.
She regularly organizes and attends events and showpieces such as scientific conferences, parties, and talent shows.
After the events in "Mortal Recoil," Princess Bubblegum is afraid of her own mortality. She worries what would become of the Candy Kingdom should she die, as pointed out in the episode "Goliad" (no reference is made to the Earl of Lemongrab returning). She considers the possibility of living forever is not scientifically possible yet so she creates an heir in the form of Goliad.
Aside from her scientific prowess, she has many abilities and talents. She has spoken German in "What Have You Done?," "Go With Me," and "Slumber Party Panic," and is capable of understanding Lady Rainicorn, who speaks Korean. In "What Was Missing" she was able to play BMO as a high-tech instrument, and in "Dream of Love," she combined her scientific abilities with her musical talents at her concert. She is a good whistler and participated in a Whistling Choir Death Match Championship. She is also an ambidextrous writer as she wrote with her left hand in "Slumber Party Panic" and "Goliad" and her right hand in "Five Short Graybles" and "Burning Low."
Princess Bubblegum's scientific aptitude is shown in "Slumber Party Panic" where she concocts a potion to reanimate dead Candy People and "Five Short Graybles" when she creates the most perfect sandwich that has ever existed. She also created Lemongrab, Goliad, and Stormo in her lab.
In "Lady & Peebles," she shows her capabilities in fighting when she fought in hand-to-hand combat with Ricardio. She also demonstrated her strength when she carried an injured Lady Rainicorn, as well as healing and rescuing Finn, Jake, and the Ice King when she brought them to the Candy Kingdom.
Her crown and matching earrings are capable of blocking the wearer's mind from The Lich's influence, as she reveals in "Mortal Folly."
Princess Bubblegum dresses as a traditional princess in a flowing pink gown and a golden tiara with a turquoise gem at the top. Her skin is usually colored light pink. She has long pink bubblegum hair which covers her ears and is actually made of bubblegum, as shown in "To Cut a Woman's Hair" when Finn gives the Tree Witch the piece of it. She has fifteen oufits in the show besides her regular dress. In "Trouble in Lumpy Space" she wears a white gown with purple sleeves and pink ruffles with purple flats. In "The Other Tarts" she wears a ball gown that resembles a tart while the gown covers her feet with a pink underdress. In "The Real You" she wears in the beginning a yellow T-shirt with a red rainicorn on it with white shorts and knee high white socks with pink sneakers. She wears a science suit in the same episode. In "Death in Bloom" she wears a wavy fuschia and magenta dress and in that episode her hair after eating the Princess Plant she gets a shorter bob. In "Susan Strong" she wears a light blue tutu and dress with a light pink sweater with flats and in that episode a dress with blue,torquiose, and light blue shading. In "Go With Me" she wore a blue dress with it going to her shoulders and the fact that in "What Was Missing" when she said that she wears a shirt gave to her by Marceline even though for pajamas she wore a yellow and pink polka dot night gown. In "Video Makers" she wore a pink sweater and purple jeans and when she was filmed she wore a white gladiotar dress. In "Mortal Folly" she wears a purple and pink meditating outfit. In "Wizard Battle" she wore a Purple dress with the it being very puffy and pink collar and magenta shoes. In "What Was Missing" she wears a light purple sweater with a pink dress with knee high boots the colar as her jacket. She then wore in "The Creeps" she wears a mask that looks like a swan with a pink dress and matching high heels with a long pearl necklace. In "Goliad" she wears polka dotted pajamas which also contradicts the fact in "What Was Missing" that she wears a shirt from Marceline as pajamas. In "Burning Low" she wears a short pink dress with purple ruffles with high heels and a long magenta dress during the end. In "Lady & Peebles" she wears a fuschia coat and boots for most of the episode to see she is wearing a purple suit. In "You Made Me!" she wears a pink shirt with purple pants and flats. In "Reign of Gunters" she wears a gypsy dress with large yellow earings with greek purple shoes.
As a thirteen-year-old, in "Too Young," Princess Bubblegum wears a pink V-neck dotted with white top with puffed sleeves, a ballgown bottom with a big, purple ribbon around her waist, and no shoes. Her hair is shorter and curls at the bottom. When she turns back to eighteen, her outfit also changes back to her original one, and her hair grows back to its original length.