Dum Dum Juice

Dum Dum Juice (also known as "Happy Juice") is a potion created by Princess Bubblegum's Uncle Gumbald. It affects Candy People, causing them to become more docile, simple-minded, child-like, and stupid.

Background
As a child, Bonnibel Bubblegum was very lonely, living in a nearly uninhabited wasteland. She decided to create herself family members, doing so she created Aunt Lolly, Cousin Chicle, and Uncle Gumbald. She and the family began to build a candy town, but doing so Gumbald came up with the idea of building a candy city. Bonnie however did not like this idea and used a butterscotch bomb to create a lake, where Gumbald intended to build the city. This infuriated Gumbald but came up with a plan for revenge. Gumbald created his niece a "boyfriend", Skyhooks IIained in their new forms. Most people are probably unaware of their origin. It is likely that Princess Bubblegum used the Dum Dum Juice, while creating a lot of the Candy People, as most are docile and stupid. However Peppermint Butler, Cinnamon Bun (after becoming "fully baked" in "The Red Throne"), the Candy Tavern People, the Pup Gang, and some other Candy People, do not seem to be like that, showing that not all candy people have been directly affected with Dum Dum Juice.

During the events of "Skyhooks II", after Lumpy Space Princess' anti-elemental "lumps", saved Ooo possessed under the elemental spell and turning everything into it's "true form", the Dum Dum Juice was cancelled out. Thus, turning the Punch Bowl, Manfried, and Crunchy, back into, Gumbald, Lolly, and Chicle. Rumors about them spread around, as Crunchy was "missing", and people reported seeing Gumbald himself. In "Seventeen", Gumbald, Lolly, and Chicle revealed themselves to the Princess. The brought a gun filled with the Dum Dum Juice threatened to fire it at Bonnie, but Marceline was present, scaring the family away.

In "Gumbaldia" the Candy Kingdom and Gumbald's new kingdom, Gumbaldia were going to war. Finn, not liking this idea, went to confront Gumbald, trying to call off the war. After saving Gumbald's life, Gumbald thanks him, along with Jake. Gumbald, Lolly, and Chicle had dinner with Finn and Jake, calling off the war. Chicle brought out a bucket filled with "celebration juice" (which unbeknownst to Finn and Jake, was the Dum Dum Juice)and splashed it on Finn and Jake, telling them to "give Bonnie a big hug." Princess Bubblegum was thrilled to have a peace treaty, but noticed Finn and Jake's smell. Peppermint Butler went to wipe to off, but transformed into a stupid, baby-like form, to the Dum Dum Juice. After this, Princess Bubblegum, once again declared war.