Brain Drain

Mario and Luigi are fixing the king's soda machine, which happens to have 365 flavors, when Luigi's radio suddenly gives a nearby Yoshi the brain of a Koopaling! Mario and Luigi rush to Princess Toadstool, Toad, and the king, and find that king's brain has been switched also! They figure the Koopas are up to it, so Mario, Peach, and Luigi rush to Dinosaur Island where the radio station that caused it, WMUSH, is located. While on the boatride there, Mario invents a hat, which Luigi wears while accidentally turning on the radio, which switches Mario and the Princess' brains! Eventually, they make it to WMUSH, after going through several different obstacles, including Luigi getting switched with a Koopa Troopa, and they find that Iggy Koopa is up to the brain switching! They discover that the antidote to the brain switching is Fungus Up, the drink that Luigi has been trying to get a hold of the whole adventure! Everyone ends up back to normal-- except for Iggy Koopa, who they leave as a Wiggler as a punishment.