Neddy (full name Neddy Bubblegum), is a candy dragon and little-known brother of Princess Bubblegum (PB). Neddy, like PB, was born from the "mother gum," or the gum hive. When PB was born, she was gently dropped into a puddle of water. Shortly after, Neddy was dropped onto a sharp rock, causing him to scream and run away. While PB explores, Neddy terrifyingly screams through a path filled with sticks and twigs. He finds comfort sucking the nutrients from a candy tree, which then causes him to excrete candy juice.
PB has built a safe place for Neddy deep within the Candy Kingdom, where he sits alone and content suckling on candy tree roots and producing copious amounts of candy juice, which the Candy Kingdom uses for bathing and for its healing properties. He had lived there in supposed peace before the King of Ooo disturbed him, causing Neddy to run away in a panic. PB successfully brings him back home. When asked about the differences between the two siblings, she says, "People get built different. We don't need to figure it out, we just need to respect it." It is mentioned that Princess Bubblegum may be responsible for him being a Bubblegum Dragon.
Neddy has a very infantile mentality. He is extremely sensitive and easily frightened, especially by the presence of other people or creatures or even funny looking plants, to a near-crippling degree. Nearly anything outside of his extremely narrow comfort zone sends Neddy into a terrified panic, making him scream and cry and run away. His only source of comfort is suckling candy tree roots and his sister making popping noises with her mouth. The lullaby from PB can calm him because he loves his sister.