Joe Robinson (also known as Uncle Joe) is the quietest member of the Robinson family. He is morbidly obese.
He doesn't speak throughout the film, but sometimes whimpers. He has apparent childlike tendencies such as sucking his thumb when he doesn't get peanut butter and jelly on his toast, and being considered "the baby" when being comforted by his family.
In the film
He is seen sitting on his easy chair "exercising" to a weight-loss program while Grampa Bud and Lewis were looking for the garage. He is later seen at the family dinner table and loses control when he doesn't get peanut butter and jelly on his toast, but later calms down after Lewis fixes the PB&J machine. He is last seen with the family when they battle the Bowler Hat Guy and Tiny the T-Rex to save Wilbur and Lewis.
He's the only one in the Robinson family "who must have PB & J on his toast or else."
He and his wife are the only ones who are married but don't have any children in the future at the time of Lewis’ visit.
He's the only one in the family that survives in an easy-chair for mobility.