David Wheeler
Dr. David Wheeler is the main antagonist of the Batman Beyond episode "The Last Resort".
He is a child psychologist who runs a rehab clinic that supposedly treats teenagers to teach him how to be better and improve their problematic behaviors. However, this clinic is actually nothing more than a front for psychological torture of teenagers, whom Wheeler deprives of sleep and isolates them if they refuse to obey him, even mistreating those teens who are not problematic at all.
He was voiced by the late John Ritter, who also portrayed Ted Buchanan in Buffy the Vampire Slayer, Warren Kincaid in Bride of Chucky, and Richard Manning in Law & Order: Special Victims Unit.