Phineas and Ferb build a teleportation device which switches Candace's and Perry's bodies, and now they have to change them back.
Meanwhile, Dr. Doofenshmirtz has a grudge against a certain company mascot and Perry has to stop him, even though Perry is in Candace's body.
* AnimalGenderBender: Candace (in Perry's body) "sweats milk".
* AllWomenLoveShoes: Doofenshmirtz tries to take advantage of this stereotype when fighting Perry who is in Candace's body. He tries to distract him (her?) by saying "Look, a shoe sale!" before running away. Oddly enough, it works.
* BalefulPolymorph: Candace gets turned into a platypus.
* FreakyFridayFlip: Perry and Candace switched bodies because of the teleportation device.
* TalkingAnimal: Candace when she switched bodies with Perry (the Platypus).
* TeleporterAccident: How the A-plot came about.
* WouldntHitAGirl[=/=]EvenEvilHasStandards: Dr. Doofenshmirtz refuses to fight Perry in Candace's body because of this.