Belly Kid is a boy that appeared in the episode Belly Bros. In the beginning of the episode, he was not able to put his shirt on because his belly was too large. Uncle Grandpa made him a shirt but it accidentally transported him into the night wolf dimension. After him and Uncle Grandpa go on an adventure to defeat the Night Wolves and get home, Belly Kid comes to love his belly and decides he does not need a shirt. He is voiced by Zachary Gordon.
Belly Kid is a plump and chubby young boy with red hair fixed up in a forward swoop. He wears navy blue pants with light blue sneakers. Sometimes he is depicted wearing a yellow shirt t-shirt that barely covers his chest.
Belly Kid formerly had body image issues, as he confessed to Uncle Grandpa in Belly Brothers that he hated his big belly and the fact it couldn't fit into shirts. His body image issues also caused him to lack confidence, shown when he could not help Uncle Grandpa at first when they were transported to the night wolf realm. However, after the adventure Uncle Grandpa brought him on, he learned to love his body the way it is and most likely no longer has a body image issue. He also learned to be more confident with his own abilities.
He also makes an appearance in the game Reckless Road Trip a game based on the Uncle Grandpa series.