Phineas and Ferb build a teleportation device which switches Candace's and Perry's brains, 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.
Tropes:
- Accidental Rhyme: Doofenshmirtz accidentally makes a rhyme with "fun" while trying to come up with a rhyme for "evil", which he then rants about.Doofenshmirtz: As soon as I get this done, lunchtime will never again be fun! Oh great, there's a rhyme! There's a rhyme, sure, everything rhymes with "fun"!
- Actor Allusion: Sheena Easton who sang the title song for the James Bond film For Your Eyes Only, sings the "Perry the Platypus" parody "Perry the Teenage Girl".
- All Women Love Shoes: Invoked by Doof, who attempts to distract Perry (in Candace's body) by shouting, "Look, shoes on sale!" before running away. Oddly enough, it works.
- Amazingly Embarrassing Parent: Linda, who despite Candace's efforts, can't help mentioning embarrassing details about her in front of Jeremy.
- Anchored Teleportation: Phineas and Ferb watch a movie about a mad scientist creating teleportation portals that work between each other (inspiring the boys to make real ones). The scientist's Igor lampshades the pointlessness of the invention.Scientist: Eureka! Now I can teleport myself anywhere in the world!
Torbo: Wouldn't you have to take one of those teleport things there first? Oh, but then you'd already be there. It kinda renders the whole thing redundant, doesn't it?
Scientist: Do you want me to remove your tongue again, Torbo? - Animal Gender-Bender: Candace (in Perry's body) "sweats milk".
- Animation Bump: Candace's Slasher Smile when calling Linda into the garage near the end is more fluid than the rest of her expressions.
- Baffled by Own Biology: The boys' latest invention cause Candace and Perry to switch bodies. Candace has trouble adjusting to her new platypus body, like when she finds herself lactating through her pores. Perry also seems to have trouble adjusting to combat without his large platypus tail.Candace: Am I sweating milk? Being a platypus is so gross!
- Brick Joke: At the beginning when Linda says she's trying to find her missing hoop earrings, Phineas says she wants to wear the blue dress. Come the end of the episode, she's wearing the blue dress.
- Didn't Think This Through: In the movie that Phineas and Ferb are watching, the evil scientist finishes building his pair of teleportation gates, only for his henchman to point out that the way the teleporters work means that he has to lug around one of the gates to where he wants to go, therefore making the entire setup redundant.Scientist: Do you want me to remove your tongue again, Torbo?
- Does This Make Me Look Fat?: Used in the title.
- Ear Worm: Doofenshmirtz gets fed up with the "Slushy the Clown" jingle because it's been stuck in his head for a week. During the end credits, he ends up getting the "Perry the Teenage Girl" theme song stuck in his head.
- Early-Bird Cameo: The design for the movie scientist would later be used for one of the members of L.O.V.E.M.U.F.F.I.N.
- Even Evil Has Standards: See Wouldn't Hit a Girl below.
- Failed a Spot Check: Mom actually does see the boys' big idea, but due to the effects of the Shrinkinator, she thinks they're earrings the boys built her.
- Forced Transformation: Candace gets turned into a platypus.
- "Freaky Friday" Flip: Perry and Candace switched bodies because they entered the teleportation device at the same time. (This episode aired as part of Disney Channel's "Seriously Switched-Up Sunday", which also featured the Wizards of Waverly Place episode "Quinciñeara", which featured a similar use of the trope, as well as the channel premiere of Freaky Friday (2003).)
- Gratuitous Spanish: Doof suggests that he can't fight Perry when he's in the body of a girl, since it is... "¿Como se dice?note Awkward."
- Handbag of Hurt: While in Candace's body, Perry smacks Doofenshmirtz in the face with a purse. Doofenshmirtz wonders where it came from.
- I Ate WHAT?!: Candace has this reaction when, while pretending to be Perry as Jeremy fed her, Linda mentions that Perry's food is ground worms and insect larvae. She ends up having a Vomit Discretion Shot, which results in Linda putting her outside. Unfortunately, this prevents Cadance from keeping Linda from embarrassing her in front of Jeremy.
- Improvised Lockpick: Perry (in Candace's body) manages to bust out of Doofenshmirtz's trap by picking a hairpin out of Candace's hair and using it to open the lock.
- Irony: In spite of wanting to see Jeremy throughout the episode, Candace immediately forgets him and enters busting mode the moment she's back to normal.Ferb: You might want to consider bathing first.
- Jaw Drop: By Candace when she sees the teleporters have shrunk. Lampshaded by Linda:Linda: Close your mouth, honey. You'll catch flies.
- Lactating Male: While in Perry's body, Candace is able to sweat milk.Candace: Being a platypus is so gross!
- Least Rhymable Word: Doofenshmirtz discovers that it's not easy finding a word that rhymes with "evil". His dimensional counterpart is able to find one later on.
- Look Behind You: Somehow, Doof manages to distract Perry in Candace's Body with "shoes on sale".
- Mirror Reveal: After the swap, Perry does not realize he's in Candace's body until he sees his (well, her) reflection in the lower screen of his desk after being commented upon by Monogram and Carl.
- Missed Him by That Much: When Candace-as-Perry tries to show Linda what the boys did in the kitchen, she has her back turned at the refrigerator. Then Candace hears Jeremy is coming and can't let him see her like this, prompting her to run out; it's only after Candace has exited completely does Linda look up.
- Morphic Resonance: When Candace is in Perry's body, she keeps her eyelashes and some portions of her own face when speaking.
- Noodle Incident: According to Candace, Linda once did something to embarrass her at her fifth grade graduation.
- Police Code for Everything: And apparently, that includes one for a lost platypus that looks like a girl. It's a 1091P.
- Poor Communication Kills: Linda doesn't think Phineas means it when he tells her he and Ferb are making teleporters.
- Running Gag: Linda trying to find her missing earrings.
- Screw This, I'm Outta Here: Subverted: Doofenshmirtz attempts to run away when Perry plans to fight him.Doofenshmirtz: Well, I'm outta here.
Doofenshmirtz disappears in a puff of smoke only to rematerialize at the exact same spot.
Doofenshmirtz: What just happened? - Self-Parody: In the end credits, Perry's theme song is parodied as "Perry the Teenage Girl".
- Shout-Out: Slushy the Clown's pose is similar to that of Bob's Big Boy.
- Sure, Let's Go with That: When the teleporters get shrunk by Doof's Shrinkinator, Linda believes they are earrings the boys made her. Phineas decides to just roll with it.
- Talking Animal: Candace when she switched bodies with Perry (the Platypus).
- Teleporter Accident: How the A-plot came about.
- Tempting Fate: Just after Candace tells the boys they're busted, the Shrink-inator hits the teleporters before Linda enters, and she thinks they're earrings the boys built her.
- Ungrateful Bitch: Even after getting her body back, Candace still wants to bust Phineas and Ferb.
- Voices Are Mental: When they swap bodies, Candace is able to speak normally, and Perry is still able to make his chirping noise, despite them having completely different vocal cords.
- What Happened to the Mouse?:
- The shrunken teleporters that Linda thought were earrings built by the boys have not been seen since this episode.
- Right when Candace gets her body back, she becomes so focused on busting her brothers that she doesn't even bother to see Jeremy, which is what she wanted to do throughout the episode.
- Wouldn't Hit a Girl: Dr. Doofenshmirtz refuses to fight Perry in Candace's body because of this.
