Sherman Peabody Sr. is the hidden true main antagonist of the entire Duo-Franchise continuity and the sworn and mortal nemesis of Zachary Delightful who drove him to frame the teenager's children.
Born in November 1, he made plans ever since he was 3. His biggest plan started to unfold once teenage vigilante Zachary and the Resistance Movement members were born in 1999 and he organized the terrorist attacks in 9/11 though at the cost of the terrorists' lives. He then put his big plot into motion.
He then had a hand in destroying Dakota Delightful, Stephanie Delightful, Devon Delightful, James Delightful, Larry Delightful, Clint Garrison, Mordecai Delightful and a random librarian. This triggered a field of delusions for the civilians to be dunked on and they start to turn against Zachary's Myles Bot project currently consisting of country singer Aiden Romero with child services agent Achu being the first to take action. However, this leaked his true nature and intentions and Zachary and his allies are determined to stop the source and save the world from his tyranny finding many decoys and androids in the process.
Mistakenly thinking it was an endgame for the Myles Bots, he reveals himself as the true killer and tries to have Zachary and the gang killed to no avail. However, Zachary discovers the true allegiance of the Linden City Police and they join in on Sherman's plot to destroy the planet Earth. Thankfully, Captain Underpants sacrifices himself to begin destroying the Grizzly Empire devastatingly with the remaining Myles Bots' aid. Meanwhile, he gains an interest in impregnating Linka Loud for his own selfish gain.
Nice Job Fixing It, Sherman
Despite laying a fatal blow on Jack Torrance (a Myles Bot who perished in a maze of his own design) and making Zachary look bad as he forcibly tries to kidnap Lana Loud as well as impregnating Linka offscreen thus giving birth to Sherman, he realizes that he really screwed up as he engages in a bloody fight to the death with Zachary and the grown-up genius tries to kill Sherman with Lana threatening to punch a hole in his head. However, Sherman escapes with his life and decides to play dirty in order to win as he dons armor from a room dedicated to Della Duck. His attempts to break the city fail as Lana getting the Arson Flu through her family getting contaminated with a virus spreading throughout the house with Arson Flu Gas caused by Sherman results in her getting cured and closer to Zachary and the team than ever.
- He serves as the villain for his actions throughout the entire series and is the most evil villain in said series.