- Generation Xerox: They looked and acted almost identical to their modern descendants, period fashion, styles and dialects aside.
- Or Was It a Dream?: While the exact events of "Rewriting History" were said to have been All Just a Dream, the characters themselves existed as per Word of God.
- Posthumous Character: Other than the 110 year old Wayne living in a retirement home, they've all passed away.
- Uncanny Family Resemblance: No less than seven ancestors, each looking almost identical to their descendant.
- Voiced by: Christy Carlson Romano
Kim's great-great aunt, Mim was a notable reported during the early 20th century who was framed for the theft of the Electrostatic Illuminator.
- Action Girl: Although not apparently a trained fighter like Kim, she didn't shy away from a fight either and was able to keep up with Miss Go atop the Ferris wheel when fighting for the Electrostatic Illuminator.
- Acquitted Too Late: By the time evidence proving her innocence surfaces, she has long since passed away.
- Amateur Sleuth: Just a noted reporter who happened to uncover the truth behind a number of cases.
- Black Sheep: Believed to be so for the Possible family, given that she was accused of committing the crime of the century.
- Clear My Name: Jon unsuccessfully tried to clear her name. Ultimately, her great-great niece was the one who found the evidence clearing her name, long after she had passed away.
- Hero with Bad Publicity: A genuinely good person, her reputation was ruined with the conclusion of the case of the Electrostatic Illuminator and she was forced to escape into hiding.
- Intrepid Reporter: She was a noted reporter during the early 20th century. Prior to the theft of the Electrostatic Illuminator, she helped the police with a number of cases, including a warehouse arson and a missing African diamond caper.
- Kicking Ass in All Her Finery: Wearing period dress doesn't keep her from fighting effectively against Miss Go.
- No Good Deed Goes Unpunished: Tried to prevent the theft of the Electrostatic Illuminator. She succeeded, but because of an incriminating photograph, the fact that the Electrostatic Illuminator went missing and that the other suspects weren't seen by anyone other than Wayne, she took the fall for the theft.
- Properly Paranoid: Jon and Professor Demenz both thought that she was a "worry wart" concerning her hunch of a possible theft of the Electrostatic Illuminator. She was right.
- You Can't Go Home Again: After she was framed for the theft by Chief Barkin, she fled from Middleton and wasn't heard of again.
- Voiced by: Will Friedle
Ron's great grandfather, Jon was a detective of the Middleton police.
- Big Eater: Much like his great grandson, he had a fondness for tacos that he discovered at the World's Fair, and once accidentally ate Barkin's pickled egg.
- Detective Patsy: Discussed, Barkin claimed that he was used as a patsy by Mim to distract the two of them so she could pull the heist while they were discussing the addition of security to the Hall of Electricity.
- Friend on the Force: To Mim, being a constable detective who frequented her commonly enough and took her assistance with at least three prior cases.
- Undying Loyalty: Jonathan never stopped searching for the evidence that would clear Mim's name.
- Voiced by: Tahj Mowry (Young)/John Witherspoon (Present)
Wade's great great granduncle, Wayne was a young photographer for the Fair.
- Camera Fiend: An amateur photograph at the time of the World's Fair, at the time he was testing out nighttime exposures and taking shots of everything and everyone. Even in the present, he still owns a digital camera.
- Chekhov's Gunman: He's the photograph taking pictures during Professor Demenz's presentation, and can be seen leaving the Hall while Mim and Jon stay behind to talk to Demenz.
- The Cassandra: He managed to see and put together what actually happened at the World's Fair, but being a 10 year old amateur photographer, his theory didn't have as much backing compared to that of Chief of Police Barkin.
- My Greatest Failure: Accidentally taking an incriminating photograph of Mim holding the empty Electrostatic Illuminator casing has haunted him for a hundred years.
- Voiced by: John DiMaggio
Drakken's great great grandfather, he plotted to steal the Electrostatic Illuminator to make the World's Fair bow before him.
- Dastardly Whiplash: Had a number of traits that go along with the concept. The fine suit, the twirling mustache and the Zany Scheme, primarily.
- Is This Thing Still On?: While ranting on about his plan to steal the Electrostatic Illuminator, he knocked a Victrola with his elbow and turned it on, recording a portion of his plan before Miss Go made him realize it was active. After his plan went south he brought it home as a "souvenir" from the Fair.
- Karma Houdini: In spite of the attempt to steal the Electrostatic Illuminator failing, he managed to get off scot-free because of Mim taking the fall as no one could prove that either Lipsky and Go existed, much less were involved and were at fault.
- Voiced by: Nicole Sullivan
Shego's ancestor, she was Bartholomew's partner in crime.
- Badass Normal: Unlike her descendant, there's no hint that she has any sort of superpowers. It doesn't stop her from being capable of impressive athletic and acrobatic feats and fighting with Mim.
- Dark Action Girl: She showed competency in hand-to-hand fighting when she fought Mim atop the Ferris Wheel.
- Karma Houdini: In spite of the attempt to steal the Electrostatic Illuminator failing, she managed to get off scot-free because of Mim taking the fall as no one could prove that either Lipsky and Go existed, much less were involved and were at fault.
- Kicking Ass in All Her Finery: Her period dress doesn't stop her from performing the aforementioned athletic and acrobatic feats, nor does it slow her down when fighting Mim.
- Screw This, I'm Outta Here!: Rather than go back for the Electrostatic Illuminator, she jumped onto Lipsky's balloon to escape.
- Voiced by: Patrick Warburton
Mr. Barkin's great grandfather and the Middleton Chief of Police at the time of the Fair.
- Badass Beard: He sported a "Franz Josef"-style beard.
- Voiced by: Patton Oswalt
Professor Dementor's ancestor, he was the inventor of the Electrostatic Illuminator.
- Ambiguously Evil: Every other ancestor shown acted remarkably like their modern day counterpart, which would imply that Professor Demenz was as very bit villainous as Professor Dementor. However, his only presented actions were the invention and presentation of the Electrostatic Illuminator, and then being attacked during the theft. He even expressed disbelief at the idea of someone wishing to wreck havoc with the dangerous potential of his invention.
- Lightning Can Do Anything: Seemed to have been of this opinion, as when pressed about possible uses of the Electrostatic Illuminator by Jon he simply stated that it could make lightning, so it had to be good for something.
- Mad Scientist: Built the Electrostatic Illuminator, a machine that can absorb latent electricity and then discharge it. Doesn't know what to do with it.