Dr. Toadley is a Toad that appears in Mario & Luigi: Bowser's Inside Story, Mario & Luigi: Superstar Saga + Bowser's Minions, and Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. He resides in Toad Town in the Toadley Clinic. He is said to know "all there is to know about the Mushroom Kingdom" (he himself claiming that he knows everything), obtaining information from his crystal ball. He also has a tendency to ask and answer his own questions.
Mario & Luigi: Bowser's Inside Story/Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey
In Mario & Luigi: Bowser's Inside Story and its remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, Dr. Toadley is first mentioned at the beginning of the game, during the meeting held in Peach's Castle's Conference Hall about the blorbs outbreak. As he was too busy helping afflicted patients, he sent his intern to the castle in his stead.
Later in the game, after Fawful obtains the Dark Star and blocks off Peach's Castle, Mario and Luigi go to Dr. Toadley to figure out what to do about it. After Bowser shows up and is defeated, Toadley tells them about the Star Cures. He tells the group that the first Star Cure is in Dimble Wood, held by Durmite. However, Mario and Luigi remember defeating Durmite already inside Bowser, and go off to find the Star Cure.
After Mario and Luigi collect the first Star Cure, Dr. Toadley, through Birdley, informs Mario, Luigi, and Bowser that the second sage is Kuzzle at Plack Beach (though his Star Cure was taken by Bowser at some earlier time and is in the treasure room at Bowser's Castle). He also informs Bowser that Mario and Luigi already have the first Star Cure.
After obtaining the second Star Cure, Mario and Luigi return to Toadley Clinic, where Dr. Toadley tells them the location of the third and final Star Cure, which is high up in the air above Plack Beach. Before the brothers leave, Dr. Toadley tests Mario and Luigi's breathing to see if they are fit for high altitudes, where the air is thinner. Mario passes, and after Luigi fails, he tries again, this time breathing so hard the machine malfunctions and breaks the clinic's ventilation system. After testing, Dr. Toadley allows Mario and Luigi to get the final Star Cure while he fixes the machine.
After Mario and Luigi get the third and final Star Cure, they once again return to Toadley Clinic. Toadley takes the three Star Cures and combines them into the Miracle Cure, which he then immediately uses to cure the blorbs before giving it to the brothers. He also has his intern give Mario and Luigi a full set of Attack Pieces, allowing them to use the Mighty Meteor Special Attack.
Mario & Luigi: Superstar Saga + Bowser's Minions
In Mario & Luigi: Superstar Saga + Bowser's Minions, Dr. Toadley replaces Psycho Kamek from Mario & Luigi: Superstar Saga. After Mario contracts Bean Fever, Luigi is tasked with retrieving the the cure from Guffawha Ruins. Dr. Toadley's role in the game is to hypnotize Luigi to believe he is Mario, in order to give him the courage to complete the mission on his own. If Mario and Luigi revisit Little Fungitown, he will be seen trying to hypnotize himself in the mirror.