Doc Drake is a duck who is a doctor who specializes in treating dinosaurs in Unjust Desserts. He is also a self-acclaimed Koopologist. He is summoned by Princess Toadstool after Yoshi eats a Koopa Cherry and becomes sick (eating Luigi in the process), although Bowser, disguised as a Toad, attempts to call him a quack. The reader must find out if Doc Drake is reputable by solving a puzzle that features him in his office and a series of stipulations that all good dino doctors must follow:
- Good dino doctors never have fewer than five things on their desks.
- All good dino doctors have the same number of diplomas on their walls.
- If a bad dino doctor has an even number of things on his desk, he has more diplomas on his wall than a good dino doctor.
- A good dino doctor always has half as many diplomas on his wall as things on his desk.
As it turns out, Doc Drake follows all of the rules. He eventually arrives to visit Yoshi as Bowser runs away. He produces a bottle of Shrinking Potion and says that it can resolve the situation, but he has also forgotten whether Luigi or Yoshi needs to drink it, requiring the reader to complete another puzzle. As it turns out, Luigi needs to swallow it, and the doctor tries to deliver it to him by lowering it down Yoshi's throat with a length of string. Yoshi misunderstands Mario's instructions to Luigi to "drink the medicine" and attempts to swallow Doc Drake's arm along with the medicine, and in the process, the bottle is lost within Yoshi's body. The doctor then produces a second bottle of Shrinking Potion, and Mario promptly drinks it himself so that he can enter Yoshi, find the first bottle, and bring it to Luigi.
Later, after Luigi attempts to drink the medicine but accidentally swallows Mario and Bowser instead, Doc Drake says that Yoshi may also be able to be cured by having him eat a Threelip. However, Mario is not sure if it can help (requiring the reader to solve another puzzle). As it turns out, Doc Drake is right, and after eating the Threelip, Yoshi spits Luigi out. Doc Drake excitedly exclaims that he knew that it might work. He then gives Luigi some Threelip petals, causing Luigi to spit Mario and Bowser out. When asked, Doc Drake does not immediately remember how to regrow Mario, but he soon remembers that eating some Magic Daisies works. After Mario is cured, Toad asks what happened to Bowser, leading the doctor to pull out a magnifying glass and show that the still-miniaturized Bowser is being chased by an ant. He then takes his leave, though not before asking to whom he should send his bill.