"Well, well, well, Francis Monogram....... it's hostile takeover time!"
Professor Parenthesis (which, he insists, is pronounced Paren-THEE-sis) is the main antagonist of "O.W.C.A. Files." He is an evil flea scientist bent on taking over O.W.C.A. with his own army of Mecha-Fleas to take control all of O.W.C.A.'s agents to do his bidding for him. Unlike most evil-doers who are dealt by the agents, he is clearly a more intelligent and dangerous villain, always putting on a few tricks up his sleeve.
He has a habit of mispronouncing words by putting emphasis on the wrong syllables.
"You always look down your nose at me. Well, now, who's beneath who?!"
In his usual human appearance, Parenthesis has tan skin, blue eyes, and light yellow hair pointing up on his forehead. His head resembles to that of a round bracket, hence his name. He wears a white lab coat with two light-green shoulder pads, green shorts, and pink slippers.
However, this appearance was nothing more than an android to conceal his true appearance: that of a tiny blue four-armed flea wearing a white shirt and pink slippers. Parenthesis' android is also capable of procuring four mechanical tentacles as back-up weapons and a giant LCD screen to show his true face to his enemies.
He first appeared in a hologram when Major Monogram and Carl learned that all of O.W.C.A.'s agents (except for Perry and his team of trainees) have been infested with tiny robotic fleas, which resulted a lockdown on O.W.C.A. HQ. Parenthesis claimed that he knew Monogram during their young years in biology class 30 years ago, but Monogram doesn't remember him at all (even when Parenthesis successfully recalled some of the names of their old classmates). Parenthesis stated he had never been noticed by Monogram, and that he was the one who sent the robotic fleas by implanting them in the collars to infest the agents to get his attention. Parenthesis also states that he has a remote that will allow the Mecha-Fleas to take control of every agent's neural system, which will allow him to take full command of the agents' will. As he activates the remote, all the animal agents fall under Parenthesis' control and they turn against Monogram and Carl, who are then forced to hide away.
Perry and his team are assigned to track down Parenthesis and stop him in his tracks, but knowing that they are the only ones who escaped the infestation (since they're not wearing any collars and that they're out in the field), Parenthesis awaits for their arrival in his lair at the Grand Canyon, where he confines them in a death trap and explains to them about his plan. Parenthesis states that he will be having permanent control of all of the remaining agents once the Mecha-Fleas override their natural instincts in 28 minutes (per his remote). He then sets off his death trap before leaving for O.W.C.A.'s headquarters with his four remaining giant Mecha-Fleas, hoping that Perry and his friends will perish in the lair's imminent explosion. However, Perry and his friends are saved by their new member, Perry's former nemesis Dr. Heinz Doofenshmirtz, who admitted earlier that he once met Parenthesis at an evil scientist convention three years ago.
Parenthesis then arrived to O.W.C.A. HQ, just as Monogram and Carl are finally caught trying to escape. As Parenthesis gloats about his plan coming to success, he stated that he'll be using the opportunity to have the mind-controlled agents to wreak havoc around the world in order to smear the good name of O.W.C.A.. However, Perry arrives to the rescue and manages to kick Parenthesis in the face. Suddenly, Parenthesis' head just fell off, revealing to be an android. Despite this, the android was still able to function as the true Parenthesis was finally revealed to be a tiny talking flea controlling it. As the android sprouts a giant LCD screen (to show Parenthesis' true face) and four mechanical tentacles, Parenthesis had several of the animal agents to hold Monogram and Carl hostage while he and his giant Mecha-Fleas pursue Perry around the training grounds. Fortunately, Doofenshmirtz and the agent trainees manage to concoct a perfect trap for the parasites (per Perry's instructions), and Karen the Cat was able to destroy the giant Mecha-Fleas with her set of skills. Despite being cornered by the trainees, Parenthesis gloats that he still will have permanent control of the animal agents in just 5 more seconds (according to his remote). However, a household fan falls onto the android, thanks to some talking bugs, who were using the fan to fly their paper plane up to the top of O.W.C.A.'s headquarters to enlist themselves as new recruits throughout the entire special. This causes both Parenthesis' android and the remote to be destroyed, permanently disabling all the remaining Mecha-Fleas and freeing all the animal agents from Parenthesis' control for good. With his plan foiled, Parenthesis attempts to make one final attack of revenge, but Doofenshmirtz manages to capture him with a pair of tweezers. Doofenshmirtz then places Parenthesis under arrest by confining him inside an enclosed pill bottle for life as punishment for his crimes, much to the flea's anger.