Mr. Chairman is the comedic and immature head of ACME and is the main antagonist of the 2003 film Looney Tunes: Back in Action, played by Steve Martin. He has the five villainous tunes, Yosemite Sam, Wile E. Coyote, Marvin the Martian, Elmer Fudd and Taz as his assassins, Mr. Smith as his minion, the Robodog as his pet, and Mary as his secretary and loving interest.
The Chairman is first seen rambling about getting the Blue Monkey diamond to his "evil purposes" (as his minion, Bob Smith reveals it to him), and then showing interest on his Bad Ideas VP, Mary.
Later, he orders his first henchman, Yosemite Sam, to capture DJ (the film's protagonist) and Daffy Duck in his casino at Las Vegas. After they escape along with Kate and Bugs Bunny to the Nevada Desert, the Chairman contacts his desert operative (Wile E. Coyote) to destroy them, but needless to say, he fails.
At Area 52, the heroes learn that the Chairman's goal is to use the diamond's power to turn every person in the world into monkeys to massively produce ACME's machines and gadgets, then have them human again to buy them for profit.
Meanwhile, Mr. Chairman contacts Marvin the Martian and orders him to execute a breakout and get the map card DJ has, but they escape in the nick of time. His last attempt of taking the Looney Tunes out of the way is having Elmer Fudd to chase them at the Lovre Museum, but Kate's cellphone with a photo of the map to the diamond is stolen by Mr. Chairman's bodyguard, Bob Smith. The group travels to Africa and finally reaches the diamond, but the Chairman and Bob and Taz the Tasmanian Devil (disguised as Granny, Tweety and Sylvester), corners them and teleports them all to ACME's headquarters (with some minor complications). He ties Kate and DJ next to a train rail where DJ's father, Damien Drake (who was kidnapped before) is tied to, waiting for ACME's Death Train to come. Mr. Chairman then gives the Blue Monkey to Marvin, ordering him to get to ACME's satellite in order to unleash the monkey laser.
Daffy and Bugs then chase Marvin through space, trying to stop him from attaching the Blue Monkey to ACME's satellite to unleash the monkey laser. However, Daffy (as Duck Dodgers) manages to throw his beak at the satellite's antenna, unleashing only two small shots, one of which hits the Chairman, turning him into a monkey. Damian Drake, who had been rescued earlier, put him in handcuffs. When Daffy and Bugs crash through the window in their ship, Monkey Chairman runs away in horror. It is unknown what happened to him after this.