Dr. Mario

Among Mario's various personas, Dr. Mario is perhaps his most important alter ego. Trading in his plumber's overalls for a doctor's lab coat, Dr. Mario is a force to be reckoned with in the medical community. Interestingly, when Mario assumes his role as the good doctor, Princess Peach decides to become his nurse as well.

Day and night, Dr. Mario works hard in his laboratory developing cures to the new Viruses that have appeared throughout the years. The good doctor has developed special Megavitamins to destroy these viruses and cure the sick. Dr. Mario's work has provided incredible health benefits to the people of the Mushroom World. However, one cure has constantly eluded him: the cure for the common cold. In the various Dr. Mario puzzle games, Dr. Mario must toss his Megavitamins into virus-filled jars. By lining up the color of the pill to the color of the virus, Dr. Mario could defeat the germs and make the world a little less sick.

In Dr. Mario 64, Dr. Mario battles traditional villains along with the usual assortment of viruses. During the events of the game, Mad Scienstein actually steals Dr. Mario's Megavitamins and brings them to his master Rudy the Clown. Both Dr. Mario and the anti-hero Wario chase after the mad scientist in an attempt to recover the curative pills (However, Wario wants the Megavitamins so he can sell the miracle pills for profit and make himself rich). As it turns out, Rudy the Clown ordered Scienstein to steal the Megavitamins because the clown villain was sick, and needed the vitamins to heal himself. In the end, Dr. Mario recovers his Megavitamins from Rudy the Clown and continues his pursuit of the cure for the common cold.

Other Appearances
Dr. Mario is a hidden playable character in Super Smash Bros. Melee. Although dressed differently, Dr. Mario fights exactly like his normal self, Mario. However, instead of fireballs, Dr. Mario shoots Megavitamins at his opponents, and his regular yellow cape is replaced by his doctor's cloak.

One part of the Super Mario Adventures comic has Mario dressing up as a doctor. However, in this case Mario is pretending to be psychiatrist, instead of actually becoming a medical physician.

Also, in the Super Mario World TV show episode King Scoopa Koopa, Mario finishes off his healthy-eating request to a group of cavepeople with the line "Dr. Mario's orders!"