Joe Robinson (also known as "Uncle Joe") is the quietest member of the Robinson family. He is morbidly obese.
He doesn't talk but sometimes whimpers and he has childlike tendencies like sucking his thumb when he doesn't get peanut butter and jelly on his toast and is considered "the baby" when being comforted by the 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 starting to lose control when he didn't get PB&J on his toast but later calmed down after Lewis fixed the PB & J machine. He is last seen with the Robinsons when they were battling Bowler Hat Guy and Tiny the T-Rex to save Wilbur and Lewis.
It's unknown how he became obese in the first place
He's the only one in the Robinson family "who must have PB & J on his toast or else."
He's the only one in the family who survives in an easy-chair.
He and his wife are the only ones who are married but don't have any children in the future.
He's the only one in the family that survives in an easy-chair for mobility.