Jonathan "Jon" Stoppable is depicted as the supposed great-grandfather of Ron Stoppable. A detective for the Middleton Police under the command of Constable Barkin, he was the best friend and associate of Miriam "Mim" Possible. Not only did he resemble and have the same voice as his descendant (Will Friedle), he had the same personality and mannerisms as well. During the 1904 World's Fair, a new invention created by Professor Demens (Professor Dementor's supposed ancestor), Jon and Chief Barkin were there in time to see Mim leave the crime scene. Jon knew that Mim couldn't have been the one to steal it, but this clashed with Barkin and his own theory. Jon's diary which was under the wobbly leg of Ron's kitchen table would prove extremely valuable in finding the stolen invention and proving Mim's innocence. Also Jon had an affinity for Tacos just like Ron.
- As with everything depicted in the episode, except the final few moments after Kim and Ron wake to discover it was all a dream, it is highly questionable if Jon was "real". Although a likeness of his head was featured on a parade float in Emotion Sickness.