Doc Hudson is secretly the retired Fabulous Hudson Hornet in Pixar's Cars.
Doc initially presents himself as Radiator Springs' physician and judge. Lightning McQueen gradually discovers that Doc was once a celebrated racer who won three Piston Cups before a crash ended his career.
The Fabulous Hudson Hornet is a fictionalized version of the real Hudson Hornet, a car that became famous in early stock-car racing. Doc's hidden past explains both his technical knowledge and his resentment toward the racing world that moved on without him.
Doc becomes a mentor to Lightning, teaching him that racing depends on more than speed. The character's voice performance by Paul Newman also connects the film to real motorsport history, because Newman competed as a driver.