Around 800 years before the series, in "Bonnibel Bubblegum", Gumbald, along with Lolly and Chicle, were created by a lonely young Bonnibel Bubblegum. Gumbald eventually started getting ideas to build a candy city. However, Bonnibel decides to stop his plans and adds a butterscotch lake where Gumbald was going to build his city. Gumbald then became upset with Bonnie and grew treacherous to her so he started to hatch a plan: He, Chicle and Lolly created Mr. Cream Puff to serve as Bubblegum's boyfriend and to keep her busy while they plotted to overthrow her and build his candy city. He formulated a "happy juice" that would make Bubblegum a docile and simple-minded candy person. However, during his plotting, Gumbald tricked Lolly and Chicle into eating happy juice-induced cupcakes which turned them into Manfried and Crunchy, causing them to forget their previous selves. Bonnibel caught this and confronted him. Gumbald voiced his opinion that he was her equal, but she denounced him as evil. Angered, Bonnibel used her pea shooting taser to spill the happy juice on Gumbald, turning him into a talking bowl of fruit punch named Punchy.
Years later, when Lumpy Space Princess's anti-elemental "lumps", reverted Ooo back to normal from the elemental spell, Punchy, Manfried, and Crunchy, were reverted back to their previous selves. The trio immediately resumed their plans from 800 years ago, getting revenge on Bonnibel and building their candy city, which they succeed in doing.
In finding out about Gumbald's new candy city, Gumbaldia, Bonnibel is frustrated and believes war to be the only answer to defeat her uncle, much to Finn's disliking. As the Candy Kingdom prepares for war, Finn and Jake decide to confront Gumbald, to call off the war. Gumbald, Lolly, and Chicle trick Finn and Jake into believing that Gumbaldia and the Candy Kingdom could coexist and splashed Finn and Jake with a "celebration bucket" filled with some sort of "glitter juice" (happy juice), and tell the duo to give Bonnibel "a big hug". Later, Finn and Jake returned to Bonnibel and gave her the peace treaty. Bonnie was about to hug Finn, but noticed the way he and Jake smelled. Peppermint Butler then wiped them off with a towel and transformed into a dumber, baby-like Peppermint Butler. Bonnibel then realized that the glitter juice was Gumbald's happy juice and that he had attempted to have her subjected to it. Furious, she formally declared war on Gumbaldia.
After hearing that the war is back on, Gumbald unveiled his Legion of Candy Kingdom Haters: Ricardio, Bandit Princess, Samantha, Peace Master, Me-Mow, Pete Sassafras, Ash, Sir Slicer, Scorcher, the Green Knight, and a confused Ice King. Gumbald then says "It's Gum War."
The Gum War
On the battle field, both sides have sizable armies with a number of allies each. After Princess Bubblegum sounds the war horn, Finn tries to convince her to give Gumbald one last chance to surrender before the fighting starts. She agrees after being reminded of her old friend, Shoko. As a last ditch attempt to stop the war, Jake unleashes the nightmare juice given to him and Finn by Nightmare Princess, forcing him, Finn, Princess Bubblegum, Gumbald, and Fern into a hallucinatory slumber.
Inside the dream realm, Princess Bubblegum and Gumbald continue to be hostile towards each other, but eventually Bonnie apologizes to Gumbald for not respecting his vision for the Candy Kingdom. Gumbald fake-accepts her apology and agrees to end the conflict, intending to betray her, but is tripped by Lolly and once again doused in his own happy juice solution, turning back into Punch Bowl. Lolly accepts the peace agreement in his place, and Princess Bubblegum proclaims that the two kingdoms shall live in harmony, leaving the war unfought and become the shortest war in Post-Apocalyptic Earth. However, they are soon all interrupted by the sudden arrival of GOLB.
- Flame Princess
- Huntress Wizard
- Earl of Lemongrab
- Lumpy Space Princess
- Duke of Nuts
- Cinnamon Bun
- Colonel Candy Corn
- Lady Rainicorn
- Legion of Candy Kingdom Haters