Doc Hudson becomes Lightning McQueen's mentor in Pixar's Cars.
At first, Doc is the judge and doctor of Radiator Springs and has little patience for Lightning's arrogance. He gradually reveals that he was the Hudson Hornet, a three-time Piston Cup champion whose career ended after a serious crash and years of being overlooked.
Doc teaches Lightning that winning is not the only measure of a racer. His guidance becomes especially important after Lightning chooses to help another competitor rather than claim an easy victory. The relationship transforms both characters: Lightning gains humility, while Doc reconnects with racing.
Doc is sometimes confused with Strip Weathers, known as The King, who is another former Piston Cup champion. Strip is a mentor figure in the wider racing world, but Doc is the character who personally trains Lightning in Radiator Springs.