Phineas and Ferb/Tropes D To I

"Mom! Phineas and Ferb are splitting their TV Tropes page!

To get back to the main page, click here!

For Tropes A-C, click here!

For Tropes J-P, click here!

For Tropes Q-Z, click here!"

"Guard: There's no yelling allowed.
 * Daddy's Girl: It's not shown too often, but a few episodes suggest Candace has this kind of relationship with her dad, such as "It's a Mud, Mud, Mud, Mud World" and "I Was a Middle Aged Robot". And considering the fact that he's actually her step-dad, it's pretty darn cute.
 * Also, Doofenshmirtz clearly wants this kind of relationship with his daughter, she just doesn't return the favor.
 * Daddy's Little Villain: "Finding Mary McGuffin" hints that Vanessa may be on her way to becoming this. Even if she doesn't, her father seems to both think and hope this comes true.
 * It's even more pronounced in "Summer Belongs to You" when Vanessa
 * She is Daddy's Little Villain, what with her stealing her father's Catch Phrase when she's carried off by her father's Pick'emUp-Inator in "Candace Disconnect".
 * Dance Party Ending: Several episodes end in this way, such as "Dude, We're getting the band back Together" and "Summer Belongs To You!".
 * Dancing Pants: Done literally in "Out of Toon", when Doofenshmirtz attempted to create a ray that would dry his clothes after his dryer broke, but instead made one that made anything hit with it dance... which includes his clothes. "Still sopping wet..."
 * "Summer Belongs to You" features the Klimpaloon, an animated "old-timey bathing suit" that lives in the Himalayas." "NANG NANG NANG NANG NANG NANG NANG NANG NANG NANG NANG"
 * Dangerously Genre Savvy: The Regurgitator, a one-shot villain for Perry who temporarily replaced Doofenshmirtz as his nemesis (and later made Doofenshmirtz his intern). While his plan was never really revealed, it was shown that he had no intention of revealing said plan to Perry. Also his base lacked a self-destruct button (until, in an attempt to be helpful, Doofenshmirtz installed one... then pushed it), and Perry's cage had no obvious way for Perry to free himself (until Doofenshmirtz installed a release button).
 * Dawson Casting: The main group of kids have ages 15 or under, according to the creators (with Candace being 15). None of their voice actors have ages falling into that range, with one of them [Maulik Pancholy] being in his late thirties. Incredibly, he's not even the oldest - the winner of that particular honour is Kelly Hu, who was 39 when she began voicing Stacy!
 * Jeremy and Vanessa were roughly the same age as their voice actors during the casting.
 * A Day At the Bizarro: "Monster from the Id", though since it's a Journey to The Center of The Mind of a Cloudcuckoolander, it's justified.
 * A Day in The Limelight:
 * Isabella and the Fireside Girls gets theirs in "Isabella And the Temple of Sap"--which also has a Perry-parallel (complete with female supervillian) in Pinky the Chihuahua.
 * "Vanessassary Roughness" does it for Vanessa. Indeed, most of her appearances do, especially when she's with her father.
 * It also features a lot more Ferb than usual (or at least, a lot more Ferb without Phineas there to outshine him).
 * "Nerdy Dancing" gives its A-plot to Jeremy.
 * "A Real Boy" focuses on Norm.
 * Deadpan Snarker: Dr. Doofenshmirtz was definitely one of these during the Cliptastic Countdown.
 * Phineas was a minor form of this in the pilot (and, by, extension, the "Rollercoaster" episode). A few other times too, though his "deadpan" is so subtle it can be hard to tell.
 * For example, in the original version of the theme song, after the line "driving our sister insane" he replied "it's a short drive."
 * Candace has a tendency to be this at times, though deadpan isn't as common as LOUD SARCASM.

Candace: Oh, right, it's a museum, I wouldn't want to WAKE ANYONE UP!"

"Phineas: (Referring to the portal to Mars) "Don't worry, we can fix it! Heh, Candace is probably laughing about it as we speak!"
 * Linda tends to be this at times as well toward Candace. At least, in her diaries (which is given a Lampshade Hanging in "Phineas and Ferb Get Busted").
 * Can't forget Vanessa and Ferb, who can pull this off with or without talking. Also Charlene and Roger's assistant Melany, though neither show up very often.
 * Stacy is like this to Candace a lot, especially in later seasons. Who can blame her, though...
 * Baljeet, especially during the moments when he is aware of his status as a Butt Monkey.
 * Norm's old head, to an almost painful degree.
 * Just about every recurring character on the show can be this at some point, actually...
 * Dead TV Remote Gag: "Perry Lays an Egg" has this.
 * Declarative Finger: Ferb is often depicted in this pose, and delivers some of his lines with it.
 * Deep-Cover Agent: Perry the Platypus aka. Agent P
 * Deface of the Moon: Doofenshmirtz and his date turn the moon into a heart shape during their "Falling in Love" Montage.
 * Department of Redundancy Department:
 * The Old Abandoned Old-Abandoned Amusement Park in "Isabella and The Temple of Sap". Lampshaded by Isabella, then the reasoning was revealed. The amusement park was actually named "The Old-Abandoned Amusement Park", but then it became old and abandoned.
 * "Space Adventure! It's an ADVENTURE in SPACE!"
 * "Phineas and Ferb built THAT?! That's horribly unsafe and dangerous!"
 * The song "Little Brothers". The lyrics state, "You will always be my little brothers/'Cause you're younger, we're related, and you're boys."
 * "You are being invaded from space, by invaders from space!"
 * The Gloominator 300...inator
 * Best example yet: The Redundant Scribe of Redundantness, namer of the Uncrossable River of Uncrossableness and the Unclimbable Mountain of Unclimbableness.
 * Depending On the Artist: From episode to episode, and sometimes even scene to scene, the way Candace's eyes move changes. Sometimes her eyes are incorrectly animated like Phineas'--retaining shape when closed or narrowed.
 * Also, during the very few times you see him from the front, he can either look downright creepy or somehow strangely adorable.
 * Description Cut: From "Unfair Science Fair Redux (Another Story)":

(Cut to Candace on Mars)

Candace: PHINEAS!!!!"

"Phineas: Well, y'know how we do something new every day?
 * Designated Villain: Doofenshmirtz, completely and utterly, to the point where he might be a parody of this trope.
 * Design Student's Orgasm: The construction of the world's tallest building in "The Doof Side of the Moon".
 * Determinator: Just try to hold Phineas back when he's doing the impossible.
 * Candace, Isabella, and Doofenshmirtz as well.
 * Deus Ex Machina: The whole point of Perry's B-Plot is to create one of these to remove all evidence of Phineas and Ferb's activities.
 * The boys have formed a major reliance on this, to the point where the one time that their stuff wasn't cleaned up by the fight (if there even was one), they had to stay up all night just to clean it up.
 * Not that Perry and Doofenshmirtz are the only ones to clean it up. In "The Beak", the boys even cleaned up their initial project themselves, though they had a super-suit to make it go by faster.
 * In "Don't Even Blink", Phineas said he didn't even know how their projects were cleared away, but it was just too convenient to worry about.
 * By "Across The Second Dimension" its shown that Candace has begun to believe in a mysterious force that resides in the backyard dedicated to protecting the boys.
 * Devil in Plain Sight: Suzy Johnson, Jeremy's little sister.
 * Diabolus Ex Machina: Doofenshmirtz's devices occasionally create these for the characters, though they are mostly minor.
 * Doofenshmirtz has one of these when he was pitching Doof n' Puss in "Nerds of a Feather".
 * Subverted in the same episode when a giant monster starts attacking the convention...
 * Did Not Do the Bloody Research/Getting Crap Past the Radar. Ferb's grandfather describes a magic trick as "a bit of the old how's-your-father." That term refers to the sort of thing the kids shouldn't be watching.
 * In the same scene he says "I may seem like a barmy ol' git now..." Git is a mild swear word in the UK, so in UK airings the line is edited down (almost seamlessly) to "I may seem barmy now..."
 * Did Not Do the Research: The entire Sherlock Holmes series would only be around 700 pages, much less than the stacks of books they put up.
 * In-universe example: In "Candace Loses Her Head", Doofenshmirtz's plan is to drill a hole through the earth to China and build a highway. The whole molten lava thing kinda slipped his mind.
 * Doofenshmirtz wants to get rid of the lighthouse near his building because it attracts ships that make noise. Lighthouses are supposed to repel ships by warning them of rocky land masses.
 * It attracts ships like moths, to the extent than they follow it deep into the city!
 * Bulls are provoked by the matador teasingly waving the red blanket, not by the color red itself. So a red ballon standing still in the air shouldn't be enough to provoke them. Then again, these were mechanical bulls, so maybe Ferb programmed them to be angered by the color red just for the heck of it, or from his own lack of understanding (assuming that's possible).
 * In the first episode, Ferb states that platypodes are the only mammals to lay eggs. However, echidnas lay eggs, as well.
 * In-universe. Doofenshmirtz builds a ray to turn the moon around, not understanding that the moon's light side is caused by the sun's light reflecting off of its surface.
 * He remembers after the plan fails, then says that he should have turned the sun around!
 * Subverted in "Greece Lighting", in which they say their chariot races are like "the Greek gladiators". In an off handed comment in the next episode, Ferb mentions that gladiators were Roman, not Greek.
 * In the episode "'Runaway Runway", Fashion designer Gaston Le Mode laments that none of his models can properly wear his new design, which he calls "The Ultimate in Haute Couture". Haute Couture is the French name for one-off, custom-fitted clothing.
 * The security guards at the end of "Vanessassary Roughness" are holidng their nightsticks backwards.
 * Neanderthals couldn't talk (they could communicate in other ways, though). Still, Phineas and Ferb's neanderthal friend talks like homo sapiens.
 * Also, stone age people (including neanderthals) was just as smart as us. So he probably wouldn't act as stupid as he did, either.
 * Actually, recent research suggests that neanderthals could talk, only not in English, of course. So he definitely would have acted more intelligent.
 * As with other shows that decide to do a "bounce house episode", the writers treat the bounce house in Meatloaf Surprise as a glorified balloon. Real bounce houses need constant inflation to stay up because their material doesn't actually hold the air that is blown in. Helium would easily escape the bounce house, not lift it off the ground and it certainly wouldn't explode if punctured by a pin.
 * Well, it was built by Phineas and Ferb.
 * Didn't We Use This Joke Already: They build a rollercoaster. Except this time, it's A MUSICAL! The trope title is practically quoted verbatim.
 * It's actually taken Up to Eleven since nearly every single character mentions the fact that it's all happened before.
 * Did You Get a New Haircut?: Stacy clearly thinks this when Candace has actually grown two inches thanks to Phineas and Ferb's growth elixir in "Attack of the 50 Foot Sister".
 * Died in Your Arms Tonight: In "Gaming the System", dies and flickers out of existence in Candace's arms after . Cue the Big No.
 * They got better, obviously.
 * Diegetic Switch: A variation - in some songs, including the title sequence, characters can sometimes be seen playing instruments during fills and solos.
 * Direct to Video:
 * "One Good Scare Ought to Do It!" made its US debut on the DVD The Fast and the Phineas, over two months before its US TV premiere on Disney Channel.
 * "Unfair Science Fair" and "Unfair Science Fair Redux" (Another Story) made their US debut on the DVD The Daze of Summer, around a week before their US TV premieres on Disney XD.
 * "The Doof Side of the Moon" made its US debut on the DVD A Very Perry Christmas, three days before its US TV premiere on Disney Channel.
 * Disappeared Dad and Missing Mom: No mention is ever made of Ferb's biological mother, or Candace and Phineas's biological father. Word of God says what happened to them is unimportant, since the point is to portray a happy, stable mixed family. In fact, since Phineas and Candace both call Lawrence 'Dad', Ferb calls Linda 'Mum', and other than in "Rollercoaster" the 'step' in 'stepbrother' is omitted, a casual viewer might not even realize this is a blended family.
 * The chance to learn was given a tease in "Mom's Birthday", in which Linda comments "I only wish Dad could have heard it." Phineas reveals that he set up a satellite uplink--which is, of course, with Lawrence.
 * Most of the side characters only get one parent shown, if any, usually the mom. Vanessa is actually the only child/teenage character who seems to actually have two biological parents. Maybe the dads are all at work?
 * Jeremy's extended family including his parents actually makes an appearance in "Run Candace Run", though he still has yet to do anything important onscreen. Also, Isabella's mom wearing her wedding ring everywhere and making a big deal over losing it in "No More Bunny Business" makes it fairly likely(albeit not guaranteed) that Isabella's dad is still around.
 * He could be dead, might explain why he is never seen and she made a big deal over losing it.
 * Disaster Dominoes: Occasionally caused by Phineas and Ferb's inventions or Doof's inators, usually due to a chain reaction of Contrived Coincidences.
 * Disney Acid Sequence: The "Going Deep Into Your Mind" song is very, very...odd.
 * Disney Death: losing one of their lives in "Gaming the System".
 * Disney Villain Death: Happens to in "Phineas and Ferb Get Busted!"
 * Disproportionate Retribution
 * Dissonant Serenity: The boys are completely unperturbed by Candace's attempts to bust them. They've even helped her a few times.
 * Ferb remains unfazed in the face of things even Phineas reacts to. His "zany serenity" is even lampshaded in "Invasion of the Ferb-Snatchers".
 * Distracted By the Sexy: Ferb's initial encounter with Vanessa results in him taking the blueprints she was picking up and vice-versa.
 * Ditzy Genius: Doofenshmirtz. When it comes to mad science he's usually quite brilliant, as some of his -inators are clever enough to stand right up there with the boys' creations, and at least SOME of his Evil Plans have been great ideas. Then he fails to understand expressions like "carbon footprint" and "green thumb", or fails to see a flaw in his plan that would be obvious to a middle-school student.
 * Does Not Understand Sarcasm: This moment in "The Mom Attractor" shows that Phineas doesn't exactly seem to grasp the notion of it:

Candace: (Pulling a priceless false-shocked expression) Noo...

Beat

Phineas: ...Oh, well, we try to build some big project, or do something-

Candace: I'm aware of the concept, Phineas, I was just being sarcastic.

Phineas: ...Really? Hey, that was pretty good. Wow, I totally fell for it. Ferb, I totally fell for it!"

"Phineas: Dad, can I borrow your glasses? I can't see my entree....y'know, 'cause its so small!
 * Does This Remind You of Anything?: This shows up a lot. (Dr. D losing the girl of his dreams to a guy with bigger hands in "Out to Launch", anyone?)
 * "Hey Candace! The things they make us wear, huh? At least you don't have a wiener on your head."
 * "And I am not using the banana this time!"
 * Phineas, after a few seconds, decides to add: "You guys heard that too, right? It wasn't just me?"
 * "So Isabella, what'd you think of your first rainbow?" "Well, it was really pretty, but it's not my first rainbow."
 * "You just squeeze and pull and squeeze and pull and..." said by Isabella while doing very obvious hand motions.
 * She was talking about milking cows, but the point remains.
 * "Your hotdog is no match for my bratwurst!"
 * Its Star Wars! Doofenshmirtz even tries using The Force and then lampshades it.
 * Which supply the image to Visual Innuendo, so make of that of what you will
 * In "The Lake Nose Monster", Dr. Doofenshmirtz is eating chicken wings and begins to talk about genies. He looks like a stoner with the munchies, talking about the completely pointless things you talk about when high.
 * "Quad-rant... Quaaaad... rant."
 * Let's not forget the infamous B Plot in "It's About Time!"
 * In "Chronicles of Meap", there's the part where Phineas, Ferb, and Isabella are taken to a cloud.
 * Ferb: "Thats no cloud."
 * Phineas: "I have a good feeling about this."
 * Orange moss.
 * Don't Explain the Joke: Utilised occasionally;

Lawrence: Yes, I think we got that."

"The Beak: All right, let's wrap this up. Hey, my first superhero pun.
 * A Real Life example: Jeff Marsh noted in an interview that the head of Children's Programming for Disney Channel didn't understand how Stacy could become president of Paraguay in "Phineas & Ferb's Quantum Boogaloo", despite it being a throwaway gag, so Dan Povenmire concocted an explanation, which involved, among other things, dating the son of the current president and being swept into office with a "llama vote".
 * This exchange from "The Beak" episode:

Khaka Peü Peü: Well, don't quit your day job, Mr. Comedian.

Random guy: Actually, I thought it was pretty clever.

Charles: Yeah, because, see, it wrapped around the legs.

The Beak: If you didn't like that one, maybe this'll be a hit.

Charles: Yeah, see, because… because he hit him.

Random guy: I'm not an idiot, Charles."

"Phineas: You know, it occurs to me we could get hurt. I suppose the "of doom" in the name should have tipped us off."
 * Doomsday Device: When Baljeet becomes super-intelligent in "Cranius Maximus", he creates a machine that will put Earth's atmosphere on the Moon.
 * Doomy Dooms of Doom: The "Phineas-and-Ferb-edge-of-insanity-kiss-your-butt-goodbye-gravity's-a-stone-cold-sucker-nightmare-rail-skate-track-obstacle-course of doom" in "The Beak".

"D.D.: Derek Dukenson, but you can call me 'D.D.'"
 * Baljeet's Spinning Tops... OF DOOM!
 * This shows up a lot, actually.
 * Double Entendre: A G-Rated example. The lair is covered in newspaper because the new agents haven't been "trained" yet.
 * Downer Ending: "Candace Gets Busted", despite the title being a Foregone Conclusion.
 * Dramatic Gun Cock: Done by Perry in "Leave the Busting to Us!" with a magician's hat.
 * Dramatic Spotlight: Candace gets one at the end of the Aglet song, and then ruins her own big moment by both not learning the word "aglet" and by, instead of singing, going off on a rant about why aglets don't matter.
 * Dramatic Thunder: The Regurgitator has this installed in his lair, which is Lampshaded several times by Doofenshmirtz.
 * Dream Land: Phineasland.
 * Dream Within a Dream: "Phineas And Ferb Gets Busted!" is the Dream Within a Dream
 * Drill Sergeant Nasty: The Big Bad of "Phineas and Ferb Get Busted!"
 * Drives Like Crazy: At least during his driving test, Doofenshmirtz, to the point where Perry is so scared he starts signing his will on the spot.
 * Drop What You Are Doing: Doofenschmirtz drops a plate of crackers, which shatters on the floor. He was getting them so Perry could have crackers with his cheese, but to the Mad Scientist's shock, the Platypus ate the entire wheel of cheese in the few seconds it took him to get the crackers.
 * Drunk On the Dark Side: More like "Drunk on intelligence so extreme that it gives you Blue and Orange Morality that causes you to do evil deeds", but Baljeet falls under this in "Cranius Maximus".
 * Dude Looks Like a Lady: In the episode "S'Winter", Candace becomes insanely jealous of Jeremy's new exchange-student friend, who looks like a gorgeous Swedish girl from the back. Said student turned out to be....

"Buford: That's a little something I like to call "Ironing"."
 * Dude Not Ironic:

"Doofenshmirtz: See? And you thought I was just making it up!"
 * Dude, Where's My Respect?: Said by Ferb at the end of "The Beak", when no one seems to recognize his part in controlling the supersuit, and Phineas gets all the credit.
 * Dueling Shows: This article says that Disney wants it to be the new Spongebob. While the show has had a lot of success, it still has a long way to go to reach Spongebob's level.
 * There was a Take That/friendly jab to Spongebob in "Summer Belongs to You" with Phineas picking up a sponge and a starfish.
 * DVD Commentary: "Attack of the 50 Foot Sister" and "The Chronicles of Meap: More Than Meaps the Eye" each have two: a standard one by Jeff "Swampy" Marsh, Dan Povenmire & Jon Colton Barry, and an in-character one by Dr. Doofenshmirtz & Major Monogram. The former episode's commentaries are on the DVD The Movie: Across the 2nd Dimension, while the latter episode's commentaries are on the DVD A Very Perry Christmas: Bonus Disc.
 * Early-Bird Cameo: "I'm Lindana and I Wanna Have Fun" is heard as elevator music in "Are You My Mummy?" before being featured in "Flop Starz".
 * Irving gets one too-- his first appearance is in "Raging Bully" as "The last kid Buford fought". We can't see his face because he's got a toilet on his head, but still...
 * "Phineas and Ferb's Hawaiian Vacation Part 1" has a blink-and-you-miss-it cameo of Ducky Momo in the hotel gift shop, a character later given a bigger role in "Nerds of a Feather".
 * Ear Worm: Invoked. Doofenshmirtz once created a video loop scientifically created to embed itself in the listener's head in a hypnosis plot.
 * Easter Egg: During Rollercoaster: The Musical When Candace and her mom are going back to the car, the future Candaces from "Quantum Bugaloo" can be seen behind a car.
 * Egomaniac Hunter: Mitch from "The Chronicles of Meap" who captures the galaxy's rarest creatures for his personal collection.
 * Egopolis: Danville is named after creator Dan Povenmire. Dr. Doofenshmirtz also creates his own country called Doofania out of spite of his brother.
 * Who, coincidentally, is also voiced by Dan Povenmire. So he gets twice the credit.
 * Ejection Seat: Double 0-0's car in "Elementary, My Dear Stacy". Agent P accidentally activates it.
 * Elaborate Underground Base: Both Perry and Pinky have them.
 * Elseworld: the series has several episodes that break the usual setting by putting the main characters in a different time period. Examples include "Tri-Stone Area" (which featured all characters in a prehistoric setting), "Doof Dynasty" (which featured them in ancient China), "Excaliferb!" (which featured the characters in a medival/fantasy setting, although this was a story read to Major Monogram by Carl) and "Phineas and Ferb and the Temple of Juatchadoon" (an Indiana Jones spoof set in the early 20th century)
 * A similar concept is present in the story in "The Monster of Phineas-n-Ferbenstein", which shows Victorian era characters taking on the same roles as the main cast.
 * Embarrassing First Name: Francis Monogram.
 * Embarrassing Middle Name: "Is 'Candace Gertrude Flynn' your full legal name?"
 * Embarrassing Old Video: This gem. Doofenshmirtz will never live it down. It's also a bit of a Continuity Nod because he mentions the video was lost. In "One Good Scare Ought to Do It", a lot of his junk was dumped out of his aircraft.
 * Empathic Environment: It turns out that all of The Flying Fishmonger's attempts to jump McGregor's Gorge were rained out because his theme song was too dreary.
 * In the Christmas Special, Doofensmirtz's Naughty-inator causes the entire town to come up as naughty on Santa's list. A side effect is filling the sky with ominous clouds, which Phineas immediately and thoroughly lampshades.
 * Empty Shell:  are brainwashed into these in "Phineas and Ferb Get Busted".
 * The Ending Changes Everything: Done humorously in the episode
 * The End of the World As We Know It: More like "The end of the TRI STATE AREA as we know it", but a lot of Doof's plans would result in this, if he weren't so ridiculously lacking in common sense.
 * "Quantum Boogaloo" provides proof, though, that if Perry wasn't there to stop him, he would successfully turn the place into an awful dystopia. Don't know if that really counts, but it's certainly not a nice place to live.
 * Candace apparently thinks that asking Jeremy to the dance will result in this.
 * Enfant Terrible: Suzy Johnson, Jeremy's little sister. She apparently scares Buford, the bully.
 * Engrish: Invoked for comic effect in the song JPOP (Welcome to Tokyo).
 * Establishing Character Moment: Baljeet is first shown doing homework, and not comprehending Phineas pointing out that it's summer and he shouldn't have any. He is then pushed off his chair by Buford.
 * Doofenshmirtz has one involving, of course, opposing Perry the Platypus and an evil scheme, but he also spends a lot of time ranting about things that aren't particularly important, gets a humorous injury, and his scheme is grandiose, half-baked, and without gain.

"Phineas: That way when [the comet] comes back in 73 and a half years, we can all show our grandchildren! Oh yeah, my parents are cooking steaks for everyone.
 * Isabella plays it straight in Comet Kermilian.

Isabella: You had me at "our grandchildren."

Phineas: What?

Isabella: Steaks! You had me at steaks."

""Mo-om! Phineas and Ferb are making a title sequence!""
 * Candace, amazingly, got hers even before the official beginning of the first episode.

"Candace: You're giving a monkey a shower?\"
 * Even Nerds Have Standards: Pretty much describes Baljeet's reaction to Irving.
 * In "Nerds of a Feather", the convention-goers all cheer for Candace until they find out that she is a teenager in a Ducky Momo costume, then promptly drop her and walk away in disgust. Even the nerds think Ducky Momo is an embarrassment that makes them all look bad.
 * Even the Guys Want Him: Handsome!Doofenshmirtz
 * The Everyman: Phineas. He's so ridiculously mellow you might even get away with bad acts in front of him.
 * Then again, that's a good thing. He was a bit of an irritable Jerkass and impatient scoffer in the pilot (more or less the first) episode that you were suddenly glad he lost that personality in the second. It also doesn't help that his voice in the first ep is rather grating to the ears.
 * The creators did say Phineas was originally depicted to be an Annoying Younger Sibling archetype, but he had improved as the episodes go on.
 * Everyone Can See It: Phineas and Isabella, full stop.
 * Candace and Jeremy too, although they have since openly acknowledged their feelings.
 * Everyone Has Standards: Perry had thwarted many of Dr. Doofenshmirtz's schemes, no matter how silly they would get. But when his scheme was learning whale speak, just so he could get back at them for stealing his girlfriend, Perry left in disgust.
 * Everyone Hates Mimes: Doofenshmirtz clearly expresses his hatred of them in "Picture This", when he decides to trap every mime in the Tri-State area in actual invisible boxes.
 * There's also a mime that gets abused with Amusing Injuries in Paris in "Summer Belongs to You". Finally his makeup gets washed off and he exclaims, "Hey, everyone, I can talk!"
 * Everything's Better With Bob: In "The Lake Nose Monster", we get Captain Bob Webber, who eventually becomes the main characters' uncle.
 * Everything's Better With Monkeys: "Giving a monkey a shower" is one of many events listed in the Title Theme Tune.
 * And the Title Theme Tune monkey is actually in the episode "Swiss Family Phineas", with Ferb lampshadeing it. The corresponding notes even play.

Ferb: Yep. Had to be done. "Doofenshmirtz: ...the, uh... book seems to have caught up with us in real time..."
 * Everything's Better With Penguins: A quartet of musically gifted penguins appears in the Title Theme Tune.
 * Everything's Better With Platypi: He's a semi-aquatic, egg-laying mammal of ACTION!
 * "Everything's Better with Perry" is almost confirmation that Disney reads TV Tropes.
 * Everythings Funkier With Disco: "Fabulous", all the way.
 * Don't forget the disco-themed hole at the miniature golf course, complete with ABBA-styled theme.
 * You are forgetting a certain "Izzie" and her "frizzies", people!
 * Evil Counterpart: Thaddeus and Thor. (They're not evil, per se, but Thaddeus is obviously a Jerkass compared to Phineas.)
 * "Thor, I know who we're gonna out-do today!"
 * "Hey, where's Harry?" "Over here!"
 * "He's a contractor. They don't do much."
 * Vanessa isn't evil but in the song "Busted" and in the episodes "Finding Mary McGuffin" and "Hail Doofania" she does come across as a Darker and Edgier counterpart to Candace.
 * Funny that she's curvier than the more angular and sharp-edged Candace then...
 * As her Clothing Switch with Candace made incredibly obvious.
 * Evil Gloating: Doofenshmirtz. As a matter of fact, in "One Good Scare Ought To Do It!", Doof gives Perry a presentation of how he planned the day. First board: Perry bursts in, *moves to another board* Perry gets trapped, *moves to another board* Doof pretends he didn't know he was coming, *moves to last* and he makes a presentation showing how he had planned it out, complete with a picture of him pointing at a board with a picture of him pointing at a...you get it.
 * And a later one, wherein he shows relatively the same type of presentation but in a pop-up book form.

"Doofenshmirtz: And now, Perry the Platypus, prepare to witness a truly petty act, brought on by my own mindless jealousy!"
 * Evil Is Hammy: Doofenshmirtz, which has bee lampshaded multiple times.
 * Taken Up to Eleven by The Regurgitator.
 * Evil Is Petty: Doofenshmirtz is pretty much the poster boy, with pretty much all of his schemes meant to deal with whatever little annoyance is bugging him at that particular moment.
 * And like everything else, lampshaded at one point:

"Doofenshmirtz: Behold, The-Wrapped-Up-In-A-Nice-Little-Bow-Inator! I bet you're wondering what it does."
 * Evil Laugh: Doofenshmirtz obviously enjoys indulging in this. For added fun, in the Take Two interview with Neil Patrick Harris, Doofenshmirtz, playing to Neil's own stint as a Mad Scientist, challenges him to a contest of these. Neil wins when his manages to summon Dramatic Thunder.
 * Evil Poacher: Mitch in "The Chronicles of Meap".
 * Evil Redhead: Doofenshmirtz's girlfriend from the episode "Chez Platypus" even has a tattoo commemorating her love of evil.
 * Serving as an inversion are Candance, Linda and Phineas, unless you really want to stretch Candace's Villain Protagonist role.
 * Evil Sounds Deep: Subverted. One of Doofenshmirtz's plans was even devised out of his frustration at lacking a deep voice. Then again, Neil Patrick Harris once beat Doof in an Evil Laugh contest because he could pull this off.
 * Evolutionary Levels: As seen in "Hawaiian Vacation" with the de-evolutionator.
 * Evil Has An Interesting Flavor: One of Doofenshmirtz's ancestor's potions.
 * Exactly What It Says On the Tin: Pretty much everything Doofenshmirtz builds. Lampshaded a couple times:
 * He describes his 'Misbehave-inator' as doing "pretty much what the name implies, really".
 * When he reveals his 'Make-Up-Your-Mind-inator', he briefly wonders if the name is too precise.
 * Subverted and lampshaded when Doofenshmirtz builds the Retire-inator, not to make someone stop working, but to get back at him for running over his foot in his automobile and putting him in a cast. (Get it? Re-tire? Because they "tire"'d him, and now he's "re-tire"'ing them?) He then points out the retire-inator for retiring... complete with crosswords and a cat for him to pet.

"You will always be my Little Brothers, 'Cause you're younger, we're related, and you're boys."
 * "SPACE ADVENTURE! It's an adventure in spaaaaaace!"
 * Stacy's song "Little Brothers".

"Phineas: Judging by my chronometer it should be just about time. Only one thing left to do.
 * Subverted with the Sea of Razor Sharp Rock Spires, which is a land of pillows.
 * Executive Meddling / Network to The Rescue: After hearing "Gitchie Gitchie Goo", Disney executives asked for a song in every episode. Marsh and Povenmire complied, including at least one song in each new episode, and inserting a song into as many semi-completed episodes as possible. Most would agree this was a positive development.
 * There's also an in-universe example in "Nerds of a Feather". Doof pitched a show to a Hollywood producer, but made a Rage Quit when said producer suggested to give Perry a girlfriend. The show was made anyway, and Doof lampshades at the end that he was probably right.
 * This example is probably also an in-joke, as "give the platypus a girlfriend" was an actual suggestion given by Disney regarding the show, according to a Wired article about it.
 * Exploding Calendar
 * Expository Theme Tune
 * Expospeak Gag

Baljeet: You mean test the resiliency of our cartilaginous collusion with vigorous application of weight and velocity?

Phineas: Exactly; let's jump on it!"

"Buford: Cool clubhouse!
 * And in the Christmas special:

Phineas: Oh no, this is not, how you say, a clubhouse. This is the ultimate rest and relaxation lounge perfectly tailored to the jolly rubenesque world traveler.

Beat

Phineas: It's a rest stop for Santa."

"(The group's bubble is getting closer to a very pointy sculpture)
 * Also in "Bubble Boys":

Gretchen: With our angle of descent, leaning will be ineffectual!

(The group lets out a collective "What?")

Gretchen: We're gonna crash!"

"Candace: Oh, I get it, big lesson. Yeah, well I guess I learned it wouldn't be too hard to ask Jeremy out if he were growing out the back of my head!"
 * Expressive Mask: Albert's glasses change with his facial expressions. Sometimes.
 * Eyedscreen: Used when Candace stares down her rival for the Hot Dog Stand job in "Unfair Science Fair".
 * Expy: Gretchen is really smart, has reddish-brown hair, and wears glasses. Doesn't she remind you of another Gretchen?
 * Eye Scream: In a scene 20 years in the future in the episode "Phineas and Ferb's Quantum Boogaloo", Perry throws dentures at Doofenshmirtz, causing the false teeth to bite his eye.
 * 555: The Fletcher's cell number.
 * Face Heel Turn: Balloony against Doofenshmirtz during "The Chronicles of Meap".
 * However, he's a balloon, so his Face Heel Turn consists of not following Doofenshmirtz.
 * Not to mention he was abandoning one villain for another.
 * Face Ship: Dr. Doofenshmirtz has a monster truck shaped like his own head. Also his Sandwich-Suit-Removinator.
 * In a less obvious example, Perry's hovercar is shaped like him.
 * Professor Poofinplotz has a facerobot in her episode.
 * Failure Is the Only Option: For both Candace and Doofenshmirtz.
 * Doof, however managed to succeed at least two times - he got rid of the lighthouse and made mountains out of the mole hill.
 * Isabella as of lately whenever she tries to invite Phineas to a date without Ferb.
 * Fake Brit: Averted with most British characters.
 * Fake High: Inversion/parody/whatever of this trope happens to Candace in "The Ballad of Badbeard". She touches some orange moss in the woods, which she was told causes wild hallucinations and begins acting insane, "thinking" Perry is a spy, imagining a sassy, anthropomorphic zebra speaking to her, and confusing a self-destruct button for a vending machine. At the end of the episode, after her "recovery", her grandmother explains that it is actually blue moss that causes hallucinations, and that the only reason Candace was "crazy" was because of the "power of suggestion." Just then, Candace touches some blue moss.
 * False Reassurance: Isabella is a bit wary when Phineas is about to launch her to the treehouse platform with a tube-swing cannon, but he says they haven't missed yet...because she's the first passenger.
 * Fan Disservice: Doofenshmirtz in the episodes "Monster from the Id" and "Remains of the Platypus", especially the latter. People like him really shouldn't show off in their underwear...
 * Fandom Rivalry: Mocked in "Nerds of a Feather". It has a plot where Fandom Rivalry at a con erupts into an "inter-genre geek war" between fans of two movie series, one sci-fi and one fantasy.
 * Fanfic Fuel: Phineas and Candace's never-been-seen-or-spoken-of biological father and, to a slightly lesser extent, Ferb's never-been-seen-or-spoken-of birth mother. It would honestly be accurate to say that at least one-third of all fanfiction written for this series at least touched on this subject.
 * Fan Service: A surprising amount. See the entries for Bare Your Midriff, Beach Episode, Hartman Hips, Modesty Towel and Zettai Ryouiki. Then there are the videos (especially the extended versions) of "Busted" and "Squirrels In My Pants". And Vanessa...pretty much always.
 * Linda's showgirl dress at the end of "Phineas and Ferb Interrupted", anyone? Whooo-eee.
 * Fanservice Extra: Plenty, the most known of which are the background dancer's for "A Real Boy" and "Hey Ferb".
 * Fantastic Aesop:

"Candace: Or you could have made a gigantic slingshot and shot us back.
 * Fantastic Voyage Plot: "Journey to the Center of Candace", complete with a micro sub.
 * Fantasy Helmet Enforcement: Done to the point of parody/Lampshade Hanging.
 * Fashion Show: "Runaway Runway"
 * Phineas and Ferb also host a smaller one during their Mom's birthday to showcase the sundress they got her as a present.
 * FemBot: Baljeet gets fembot backup singers during his "Taking on the Big Brain" musical number.
 * Fiery Redhead: Candace.
 * Filk Song: Done to one of their own songs, Busted is transformed into Rusted.
 * First Kiss:
 * Five-Man Band: Team Improbable, a cartoon superhero group who are all Author Avatars of the boys and their friends (who themselves could also be considered a Five-Man Band).
 * In general, Phineas and his friends form one:
 * The Hero - Phineas (Doubles as The Face)
 * The Lancer - Ferb
 * The Smart Guy - Baljeet (sometimes Isabella)
 * The Big Guy - Buford
 * The Chick - Isabella
 * Sixth Ranger - Irving (in a way)
 * Team Pet - Perry
 * Flag Drop: During Ferb's Rousing Speech in "The Lizard Whisperer", a truck with a Union Jack on the side drives up behind him.
 * An American flag appears behind the Fireside Girls while they are singing their anthem in "Isabella and the Temple of the Sap"
 * Flashback With the Other Darrin: In "Phineas and Ferb's Quantum Boogaloo", the boys who see and take the flyer for the rollercoaster have different voices from the same boys in the first episode.
 * Flat Character: All of the Fireside Girls sans Isabella, who pretty much just exist to help Phineas and Ferb in various projects.
 * Doesn't stop the Ferb/Gretchen shippers.
 * Then again, some episodes, particularly "Isabella and the Temple of Sap", seem to be giving the other Fireside Girls (or at least Adyson, Gretchen, and Ginger) more visible personalities, so they seem to be moving away from this.
 * Parodied with the twin sister of Phineas and Candace's grandmother, who lives in a closet until one time a year where she participates in a prank.
 * Jeremy is seen by some as this, as just "Nice Guy who cheers up Candace".
 * Originally. Around mid-Season 2 onward, he has been developed much more as a character.
 * Flawed Prototype: Jerry the Platypus, from "Cheer Up, Candace!".
 * Doofenshmirtz makes a couple of himself in "Run Away Runway".
 * The unstable speed boots. Of course Candace was the one who ended up using them.
 * Fluffy the Terrible: The Big Bad of "The Chronicles of Meap" is a villainous-looking space poacher with the unassuming name of Mitch.
 * Also is Doofenshmirtz's mentor, Professor Destructicon. Kevin, to his friends.
 * Flushing Toilet, Screaming Shower: The credits of "The Backyard Aquarium", but replacing the "toilet" with a hose.
 * Food and Animal Attraction: There's an entire song where this happens. Candace gets acorns in her pants, and of course, squirrels follow...
 * Foot Focus: In "Spa Day", Candace and Stacy get their backs walked on by barefoot Fireside Girls, including closeups of Holly's, Candace's and Stacy's feet. The scene briefly shows five pairs of feet before the rap starts.
 * Follow in My Footsteps: Subverted in "Minor Monogram". Monogram's son, Monty actually wants to fight evil, but Monogram thinks he doesn't, and allows him to do what he wants.
 * A more complex example than that: Major Monogram was himself a straight example of his trope, and ended up becoming convinced that his son wanted the same thing he did: to escape the family legacy and become an acrobat. He ended up pushing Monty to become an acrobat instead, making it an unintentional example of "Follow In The Footsteps I Wanted To Leave". He does eventually get the hint that Monty's fine with fighting evil, though.
 * Forgotten Anniversary: The main focus in "Dude, We're Getting the Band Back Together".
 * Foreshadowing: From "Swiss Family Phineas":

Phineas: Not bad. Mind if we use that someday?"

"Candace: You may be a pain, but you are my brother."
 * Formally-Named Pet: In one episode Doofenshmirtz took in a cat and named it Mr. Fluffypants, after his uncle Fluffypants.
 * Candace had a bunny for one episode that she called Mr. Cutie Patootie. Turned out he was an enemy agent trying to find Perry's lair.
 * For the Evulz: A lot of the "evil" things Doof does are for no reason other than for being evil.
 * For Want of a Nail: In "Phineas and Ferb's Quantum Boogaloo", future Candace discovers that busting her brothers on the first day of summer results in the tri-state area becoming a Dystopia ruled by Doofenshmirtz.
 * Four-Fingered Hands: All of the characters on the show only have four fingers. Naturally, this is not even mentioned or addressed most of the time... until the "Musical Cliptastic Countdown" episode, where it is Lampshaded. Dr. Doofenshmirtz says that they're at the "final four" songs, and he holds up a hand with all of his fingers extended, except for his thumb. He looks at his hand and extends his thumb in order to show four fingers.
 * Four-Temperament Ensemble: The four boys in the main circle of friends:
 * Phineas is Sanguine.
 * Ferb is Phlegmatic
 * Buford is Choleric
 * Baljeet is Melancholic
 * Fourth Wall Mail Slot: Candace has a blog that readers can e-mail questions to. There are options for e-mailing other major characters as well, though those messages appear to only be used for advertising on the website rather than direct interaction with the audience.
 * Fragile Speedster: "Run Candace Run".
 * Well, she is Made of Iron and took a Watch Out for That Tree gag like a champ.
 * Freaky Fashion, Mild Mind: Vanessa dresses like a typical Goth, but is generally pretty down to earth.
 * Freaky Friday Flip: Perry and Candace swap bodies for the duration of "Does This Duckbill Make Me Look Fat?".
 * Combined with Voices Are Mental and, somehow, Gender Flip, assuming that Perry is indeed male. Perry's body gains eyelashes and starts sweating milk.
 * Freeze Frame Bonus: Many recurring characters can be spotted this way, the best example being the Mix and Mingle Machine, which contains among others Danny and a Badinkadink.
 * In "She's the Mayor", toward the end of the time-lapse, a Perry-Doofenshmirtz fight takes place. Some artistic liberties were taken; at one point Perry can be seen dressed as a typical lazy husband sitting on a recliner and watching TV while Doofenshmirtz irons clothes. Wearing a dress.
 * During the same sequence there is freeze-frame taken during the time of Candace's run for the mayor with a huge poster on a wall, similar to Barack Obama's Hope poster.
 * French Jerk: Linda and Charlene's teacher in cooking class.
 * Freudian Excuse: Dr. Doofenshmirtz is fond of these. He's certainly earned his right to them.
 * Brother Or Idol Decision: In "Traffic Cam Caper", Candace gets to pick either the CD that will bust her brothers or to Phineas. Naturally she goes with Phineas.

"Isabella: Phineas is The Beak?!
 * Though it looked like it wasn't until after the CD dropped that she reached for Phineas.
 * In "The Lemonade Stand", Candace has a falling-out with Stacy, and reaches a point where she has to choose between a perfect opportunity to reveal the boys' activity, or catch up with Stacy to apologize. Again, naturally, she goes with Stacy.
 * Fruit Cart: The giant bowling ball destroys one of these.
 * A vegetable cart gets destroyed during the Christmas Special.
 * Full-Name Basis: "Ah, Perry the Platypus!"
 * To a less ridiculous extent, Monogram insists on calling Perry Agent P. He's called him 'Perry' all of twice, one of which was fulfilling the 'Where's Perry?' quota.
 * Also "The flying car of the future, today!" from "Phineas And Ferb Get Busted!"
 * Funny Afro: Near the end of "Robot Rodeo", Isabella's hair gets frizzed up so much it looks like two big afro puffs.
 * Funny Background Event: In "The Lemonade Stand", Candace takes a walk around Danville regretting on how she puts busting over Stacy, and she was too focused that she didn't realize that everywhere she goes, stands/balloons/blimps/boards/posters on Phineas and Ferb's lemonade stand appears. This makes Candace unable to bust her brothers.
 * In "Canderemy" the dog Phineas and Ferb made chews on a tree like a stick, digs a giant hole, and finds a dinosaur.
 * Funny Foreigner: Baljeet and Doofenshmirtz.
 * Fun With Acronyms: Played with a lot.
 * The Buoyancy Operated Aquatic Transport and Metropolitan Oval Aquatic Trench from Interview With a Platypus.
 * League Of Villainous Evildoers Maniacally United For Frightening Investments in Naughtiness from Nerdy Dancin'
 * "Summer Belongs to You" gives us the Organization Without a Cool Acronym.
 * The Doofenshmirtz Institute of Evilology has a rather succinct, and somewhat evil, message encoded in its name.
 * Fun Personified: Phineas, in spades.
 * Fun With Flushing: In one episode, Perry goes to his lair by flushing himself down a toilet.
 * Gadgeteer Genius: Phineas and Ferb. If you go to the Western Animation section, they're the first ones on the list.
 * Game Breaker: A near-literal case: Candace's Hairdryer in "Gaming the System".
 * Genre Buster: Exaggerated/parodied in "Mommy Can You Hear Me?", when it's revealed that the boys have made a book series that fits into just about every literature genre imaginable.
 * Genre Blind: Isabella in "The Beak", Lampshaded by Candace.

Candace: (sarcastically) Hey! You just got your 'Ah-Durr' patch!"

"Candace: (to Linda) Anyway, when I bust them, everything will just magically disappear. Always happens. You'll see. Well, you won't see. I'll see. Trust me."
 * Monogram in the DVD commentary for "The Chronicles of Meap" with regards to Medium Awareness.
 * Genre Savvy: Doofenshmirtz shows exceptional knowledge of the "Evil Scientist Vs. Secret Superagent" schtick. Strangely, he never uses this knowledge to his advantage.
 * On one occasion, he used his knowledge of Perry & the other animal agents always winning to his advantage; they had all been captured to prevent their interference in a "Inator Creator" contest, only for Doofenshmirtz to release them so that they destroyed all of the other Inators whilst he worked on his entry, the "Destroy-Rodney's-Inator-Inator".
 * Similarly, after the first few episodes, Candace begins to master the series of events that unfold every time she attempts to bust her brothers to her mom. And like Doofenshmirtz, she rarely actively tries to use this to her advantage.

"Monogram: Why is his head in a cloud.
 * Not just that, but even Linda eventually starts to get the hang of things. So much so that the one time Candace doesn't call her mom (like she would normally do), Linda gets genuinely worried and goes home immediately.
 * And that one was only in the 2nd episode.
 * Candace appears to have reached a level of genre-savviness where she realises she can neither bust her brothers nor give up trying, and can only bemoan her fate or achieve some kind of Animal Man-style fourth-wall-breaking revelation and Rage Against the Author.
 * In the movie, she realizes that everything weird disappears before her mom can see, regardless of who made it. Naturally, this is put to good use.
 * The super computer is the ultimate incarnation of Genre Savvyness.
 * The No Fourth Wall character commentary for "The Chronicles of Meap" established Doof as this in terms of Medium Awareness--in contrast to Genre Blind Monogram, he's aware of Hammerspace and thought bubbles.

Doofenshmirtz: That's a thought bubble. You've never seen a thought bubble?

Monogram: It's a thought bubble...

Doofenshmirtz: You live in a cartoon universe, you've never seen a thought bubble...

Monogram: I guess I've just never really noticed it before.

Doofenshmirtz: Well, that's what they call--it's, it's a convention in cartoons..."

"Candace: Yes, they're building something. But I've realized that the problem is I always jump the gun. So I'm gonna wait until just the right moment... (stops and looks panicked)
 * On the other hand, Monogram appeared to be savvier with regards to plot advancement.
 * Germans Love David Hasselhoff: Two jokes about how much the French love Jerry Lewis in one ten minute episode? That has to be a record, surely?
 * Get a Hold of Yourself, Man!: Isabella does this to Phineas to snap him out of his temporary Heroic BSOD in "Summer Belongs To You!"
 * Get Back to The Future: "It's About Time!"
 * Getting Crap Past the Radar: See here for more details
 * Giant Floating Baby Head From Nowhere
 * Giant Floating Baby Heads Make Everything Funnier
 * Giant Wall of Watery Doom: Subverted twice, and then played straight in the episode "The Belly of the Beast". Candace also lampshades it twice.
 * "Gift of the Magi" Plot: Averted by Jeremy and Candace in the Christmas Special: each of them got rid of something they had already been planning to get rid of, except that instead of buying something for themselves they got the gift for the other. So actually, everything worked out perfectly.
 * Gilligan Cut: From Phineas and Ferb's Quantum Boogaloo:

Stacy: Candace? Hello?

(cut to Candace running with her phone in her hand)

Candace: They're on the move, I'll bust them now! I'll bust them now!"

"Phineas: That didn't take as long as I thought it would.
 * Girl/Guy Of The Week: Mishti (to Baljeet), Coltrane and Chad to Stacy, Charles to Candace, and all of Doof's dates.
 * Go-Karting With Bowser: Perry the Platypus helps Doofenshmirtz set up his daughter's birthday party.
 * And helps him practice kickball. And goes to a science fair with him (and goes shopping with him to prepare for the fair). And hangs out with him at his condo in the suburbs. They even exchange gifts at Christmas, though Perry's not all that pleased with his.
 * This also happens a lot with Candace and the boys. "It's a Mud, Mud, Mud World", "Tree to Get Ready", and "Lawn Gnome Beach Party of Terror" are just three examples. Also, Stacy and the boys in "Put That Putter Away".
 * Gold Fever: The Crazy Old Coot. "If ya find any gold it's mine!"
 * Good Parents: Linda and Lawrence are a Happily Married couple raising the children from their respective first marriages together, and while mostly oblivious to their exploits, take care of them very well.
 * From the same series, Doofenshmirtz to his daughter Vanessa, who begins to realize over the course of the series that he's not so bad a father despite his usual doting. Averted, however, by Doofenshmirtz's own parents, who were basically horrible. In fact it could be interpreted that his own horrible upbringing is the reason he so desperatly wants to be a good father.
 * Good Times Montage: Many examples. Often combined with Hard Work Montage when it is a montage of Phineas and Ferb building their big idea for the day. Accompanied by either the "Quirky Worky Song" or the song of the week.
 * One episode had their project already set up without a montage.

Ferb: I know. Usually it takes us at least a montage."

"Doofenshmirtz: For your information, I've had these WAY before I met you."
 * My Nemesis.
 * Goofy Print Underwear: In "Bubble Boys", Doofenshmirtz wears a pair of Perry the Platypus print undies.

"Doofenshmirtz: Wait! Wait! I can't fight you when you're dressed as a girl! It's so... cómo se dice... awkward.
 * Gorgeous Garment Generation: The "Ball-gown-inator"
 * Gosh Dang It to Heck: Phineas isn't even street enough for that.
 * Gossip Evolution: Happens in "Does This Duckbill Make Me Look Fat?" due to Phineas and Ferb's confusing missing pet poster.
 * G-Rated Drug: The orange moss in "The Ballad of Badbeard", which causes Candace to act almost exactly like she's high when she touches it, complete with a psychedelic background and music.
 * Also, Phineas' apparent addiction to building things in "Bully Bromance Breakup" is treated suspiciously like this, including him getting some sort of withdrawal and relapse.
 * Grappling Hook Pistol: Agent P is very adept with his.
 * Gratuitous Spanish: From Doofenshmirtz no less, though whether he's actually fluent is debatable. If he is, he has a strange sense of humor.

Doofenshmirtz: We did it! We did it! Lo hicimos! We did it!"

"Doofenshmirtz: As they say in Mexico, do svidaniya! Down there, that's two vidaniyas."
 * This was even subverted in one episode. Doofenshmirtz said something along the lines of;

"Doofenshmirtz: You are feliz naviDEAD to me! See, that's Spanish..."
 * do svidaniya means goodbye in Russian. So, subverted TWICE
 * From the Christmas special...

"Phineas: Siga sentado, por favor!"
 * Recycling a quick gag in the original pitch that didn't make it, Phineas does it, too.

"Doofenshmirtz: Maldito seas Perry el Ornitorrinco!!!!!"
 * And don't forget that line of every episode...

"Candace: I just found out why cows and frogs don't date."
 * Gravity Is a Harsh Mistress: In "Phineas and Ferb's Quantum Boogaloo", future Candace climbs a tree to eavesdrop on her time travelling brothers. This works until she thinks "Wait a minute. Isn't this a virtual tree?" and immediately falls through the hologram.
 * Great Big Book of Everything: The Fireside Girls manual, containing information on advanced car maintenance, traveling through time or space, and combating giant robots.
 * The Greatest Story Never Told
 * Green Aesop: Parodied when one of Doof's schemes involved making large carbon footprints. He didn't understand what that meant, so he just created a giant foot out of carbon paper with which to stomp things.
 * Grievous Harm With a Body: In "Greece Lightning", Buford uses Baljeet and his helmet like an axe to remove the obstacles that get in his way during the chariot race.
 * The Grinch: Subverted in the Christmas Episode. Doofenshmirtz, the villain, who hates just about anything related to the plot, admits that he actually doesn't hate Christmas and wonders what's wrong with him.
 * He has an INTENSE BURNING INDIFFERENCE.
 * This bothers him so much that his Christmas wish is...to develop a hatred of Christmas.
 * Groin Attack: Baljeet suffers from an extremely painful one in "My Fair Goalie".
 * The Grotesque: Candace's "Senor Frowg" Bangoroo doll. Seriously.

"Bystander Who Looks Suspiciously Like Dr. House, For Some Reason: You monster! Now I'm wet!"
 * The Gump: Though not Phineas and Ferb themselves, the Time Shift episode reveals that their ancestors apparently built the wheel, the Great Wall of China, the car, the Panama Canal, and the English language.
 * Hair Decorations: Isabella, who sports a cute pink bow, as well as Stacy, who wears a blue one.
 * Halloween Episode: "That's the Spirit", where the boys encounter a strange boy named Russell on Halloween night who is convinced his house is haunted. Meanwhile, Agent P has to stop Doof after he becomes a werecow.
 * Also, though it doesn't take place during Halloween, "One Good Scare Ought to do It" also counts.
 * Hammerspace: In a unique case of hammerspace, it seems Doofenshmirtz came from it as a baby, seeing as neither of his parents was present at his birth.
 * Lampshaded in "Chez Platypus", as Buford claims to carry a large, conspicuous velvet rope wherever he goes. Phineas asks where he keeps it, but Buford proclaims that he'll never tell.
 * Lampshaded as well in "The Chronicles of Meap: More Than Meaps The Eye", Candace asks Meap (who wears no clothes) where he keeps all these photos.
 * Perry regularly pulls his fedora from here.
 * "Did you have that purse when you came in here?"
 * Hands-On Approach: Isabella to Phineas in "Last Train to Bustville".
 * Happily Married / Happily Adopted: The blended family is extremely tight. It's not actually readily apparent that the kids are stepsiblings, since all three refer to each other as brother and sister, and both parents as Mom and Dad; Candace in particular has something of a Daddy's Girl relationship with Dad, despite being his stepdaughter.
 * Happy Dance: Several times, most notably Lawrence's "victory dance" from "My Fair Goalie".
 * Happy Ending: Usually subverted in most episodes, to add to the comedic effect. Rarely will you see this throughout the show.
 * Probably the most straight example is the special entitled "Summer Belongs to You", where, eventually,
 * Harmless Villain: This trope seems quite common with Disney Channel villains.
 * However, "Quantum Boogaloo" showcased that if Perry was not around to stop Doofenshmirtz, he could very well do some extreme damage.
 * Well, sort of. It was heavily implied that the soccer moms were really the ones who made everything go so far downhill, Doofenshmirtz just took the opportunity to rebuild everything in his own image.
 * Doofenshmirtz's Evil Plan in "Out To Launch" was...to make shadow puppets on the Moon. Was it even worth Perry's effort to stop him?
 * In "The Beak", the villain doesn't seem to actually do much in the way of threatening the populace.

""It all began on the day of my actual birth. Both of my parents failed to show up. And on my fifth birthday, I had to throw myself my own surprise party.""
 * In "Perry Lays an Egg", after hearing about Doof's evil scheme to learn how to speak 'whale' so that he could insult a whale, Perry leaves without even bothering to stop him. Doof then follows Perry around with cries of, "Thwart me, Perry the Platypus! Thwart me!"
 * Hartman Hips: Linda and Professer Poofenplotz.
 * Heart Symbol: Isabella when she sees Phineas, especially in the first episode.
 * Heavy Metal Umlaut: Love Händel.
 * Heavy Mithril: "Epic Monster Battle" from "Excaliferb!" and, to a slightly lesser extent "Our Movie's Better than Yours" from "Nerds of a Feather" (Which also crosses over with Nerd Core)
 * Heel Face Turn: In "Voyage to the Bottom of Buford", everyone believes Doofenshmirtz has one of these when he accidentally saves a kitten. He is not particularly amused.
 * In "Meapless in Seattle",.
 * Held Gaze: ShipTeased couples on this show often employ this trope for means of instigating UST between the participants in it. For instance, Ferb and Vanessa share one when he first meets her, and Phineas and Isabella have also held each other's gaze - most notably in the special "Summer Belongs to You!", when they are stranded on the island.
 * Here We Go Again: The ending of "Phineas and Ferb Interrupted".
 * Heroes Want Redheads: Jeremy Johnson, Isabella Garcia-Shapiro, Lawrence Fletcher, and Uncle Bob.
 * Heroic BSOD: Phineas has one in the Christmas special . To a lesser extent so do the other kids.
 * Isabella's face goes completely blank at the end of "Phineas and Ferb's Quantum Boogaloo" when Candace suggests an alternate interpretation to a comment made by a future kid:
 * Phineas has one in "Summer Belongs To You" when the kids end up crashed on an island with only sand, two palm trees and a big fat ox. Phineas is unable to come up with an invention to get them back to Danville and just stammers himself to a stop.
 * Herr Doktor: Dr. Doofenshmirtz.
 * Heterosexual Life Partners: The titular Phineas and Ferb, who are inseparable and hardly ever seen on-screen without each other. Also, Candace and Stacy, Major Monogram and Carl, Perry and Dr. Doofenshmirtz and to an extent Buford and Baljeet could also apply.
 * Of the above, three pairs have had "breakup" episodes.
 * "Hey You!" Haymaker in the extended version of Gitchi Gitchi Goo http://www.youtube.com/watch?v=ocXFH054vwU
 * Hiccup Hijinks: "One Good Scare Ought to Do It!"
 * Hidden Depths: In "Summer Belongs to You", Buford speaks fluent French and quotes Voltaire. In other episodes he also drops hints of deep thinking, though he usually subverts this into Sophisticated As Hell pretty quickly.
 * Hilariously Abusive Childhood: Dr. Doofenshmirtz takes it Up to Eleven, of course:

"Monogram: Way to stick that landing, Agent P. (holds up 9.5 scorecard; Carl comes in, holding up an 8.5 scorecard) Eight and a half, Carl? Really?
 * His Name Really Is "Barkeep": The "Disembodied Reggae Space Voice" from the "Moon Farm" episode.
 * Hoist By Her Own Petard: "Candace Gets Busted". Candace insists that the intimate get together is her idea along with the fact that it's just a get-together. Just when she thinks the party is gone, it comes back for her parents to see. When asked whose party it is, it's Candace's party. If she had let the boys take the credit, they would have gotten busted. Being Good Sucks.
 * Happens to Doof numerous times, such as Chez Platypus, where his date was ruined by his own de-loveinator.
 * Hold Up Your Score: "Lawn Gnome Beach Party of Terror".
 * "At the Car Wash":

Carl: Well, sir, he did separate his feet a little on the reentry.

Monogram: Carl...(groans) Hey, is something burning over on the stove?

Carl: (runs off) My spaghetti!"

"Candace: Nobody picks on my brothers but me!"
 * Hollywood Atlas: Phineas lampshades the fact at all of England's famous buildings and locations are all just a few feet away from one another.
 * Homage:
 * In "Interview with a Platypus", Jeremy brings Candace's shoe to her when she accidentally leaves it behind.
 * Perry throws his hat in order to save the day.
 * Love Händel is an homage to eighties rock bands like Def Leppard.
 * Hot Mom: Like half the mothers in the series. Obvious examples include Linda, Mrs. Hirano, and the future Candace in "Phineas and Ferb's Quantum Boogaloo."
 * How We Got Here: "Remains of the Platypus"
 * Human Popsicle: "Boyfriend From 27,000 BC".
 * Candace in "S'Winter".
 * Humiliation Conga: Just try and count how many times this has happened to Candace.
 * This happens to Doof practically Once an Episode.
 * Humor Dissonance: Done intentionally in "Cheer Up Candace".
 * Hypercompetent Sidekick: Most of Phineas and Ferb's friends to some degree, but especially Isabella.
 * Ferb may not be officially considered a sidekick, but he otherwise has this role down pat.
 * Hypocritical Heartwarming: From "Gaming the System"

"Buford: I WAAAAAAAAAAAAAAAAAAANNNNNNNNNNNNNNNNNNNNNNNNNNNNT... nuthin'."
 * Hypocritical Humor: In "Nerds of a Feather" Doofenshmirtz puts in a random monster to wrap up his TV show pitch. The TV exec calls him out on it as "Shoddy Writing"-- as immediately afterward a random monster attacks the hall.
 * In "It's a Mud, Mud, Mud, Mud World" Linda's French cooking teacher doesn't allow cellphones in class, but that doesn't stop him from bringing one himself.
 * In "The Lemonade Stand", Candace complains that Phineas and Ferb never do anything "normal". This coming from the girl that spends every day trying to get them in trouble.
 * "I Am" Song / "I Want" Song: The twofer song "I'm Lindana And I Wanna Have Fun".
 * "I'm Me" from "Vanessassary Roughness".
 * "Fireside Girls" is a "We Are" song.
 * "The Wizard of Odd" gives us several more of these, with Buford giving a hilarious subversion.

"Phineas: Hey! I can see Stacy's house from here!""
 * I Can See My House From Here: Parodied in "Lawn Gnome Beach Party of Terror!". Phineas could see his house while parasailing...in his backyard.
 * In "Rollercoaster: The Musical!" Stacy comments that she can see the rollercoaster from her house. Cut to the rollercoaster...

"Listen to me, guys. Forget everything they told you. Creativity isn't bad! It's the best thing about you! (Sobbing) You two can do anything! And that's why I've always been secretly proud to be your older sister! What have I done?! What have I done?!"
 * I Comma Noun: The episode "I, Brobot".
 * Identical Grandson: "The Monster of Phineas-n-Ferbenstein".
 * Not to mention that Ferb looks exactly like his grandfather Reginald Fletcher.
 * Future Candace and her daughter Amanda look remarkably like the present day Linda and Candace.
 * Ferb, his father, and grandfather and even his great-grandfather all have capital F shaped heads.
 * Idiot Ball: Doofenshmirtz has a sudden drop in intelligence in "The Beak".
 * Candace seems to carry one a lot too. If only she had a device that could be used to capture an image of the mischief that her brothers are getting up to and then send that image to a similar device owned by her mother. Something like, let's see, a camera phone!
 * To be fair, she tried that once. It didn't take.
 * Fridge Brilliance: Candace has an almost eerie zen-esque level of Genre Savvy so maybe she just doesn't want to risk her phone getting destroyed, which would surely happen if it contained condemning evidence.
 * Furthermore, the sub-plot of one episode revolved around Candace and Stacy mishandling Candace's camera phone and accidentally sending a series of embarrassing photos to Jeremy.
 * In the episode "Excaliferb" Candavere accidentally spills some of her brothers' potion on herself, causing her to grow a unicorn's horn. What does she do then? Spills another one on herself, thinking it will make it go away.
 * Doofenshmirtz really holds onto this in "A Real Boy" after he's been hit by the Forget-About-It-Inator. Yes, it was a Laser-Guided Amnesia device, but it was only supposed to make him forget about what he was thinking at that moment, which was apparently the identity of Norm. He drops it again once the machine explodes.
 * Quite ironically, when Baljeet becomes super-intelligent in "Cranius Maximus", he decides to remove the Earth's atmosphere because it obstructs the view of celestial bodies from telescopes. What he does not seem to know is that this is exactly what orbiting satellite telescopes(like the Hubble) are for.
 * Identical Stranger: Princess Baldegune, who looks exactly the same as Candace.
 * I Just Want to Have Friends: Candace temporarily became this when she thought her friends had abandoned her. This resulted in her becoming the queen of Mars.
 * "I Know You're in There Somewhere" Fight: Candace is reduced to delivering a desperate and, eventually, tearful one to her brothers in "Phineas and Ferb Get Busted",.

"Ferb: I ... was weak."
 * Imaginary Friend: Linda believes this of Steve the chameleon, even though he's not.
 * Imagine Spot: Phineas asks why his usually-diligent brother got the blueprints switched in "I Scream, You Scream"; Ferb zones out in a brief fantasy of Vanessa.

"Employee: Aren't you a little young to be [Insert whatever Phineas and Ferb are doing]?
 * Isabella goes into a similar trance (which she calls "Phineasland") in "Isabella and the Temple of Sap". Apparently this happens to her frequently and the other Fireside girls clue her into what she missed while she zoned out.
 * Impossible Shadow Puppets: This is one of Doofenshmirtz's more benign skills.
 * Impossible Task Instantly Accomplished: Once an Episode
 * Impossibly Compact Folding: Phineas and Ferb loves this trope:
 * In Summer Belongs to You, Ferb unfolded a map from a roughly two by two inch square into a world map larger than the house it was leaning on.
 * Their "Plataposterior" robot is about 10 feet tall, but folds up into a square that fits in Ferb's front shirt pocket.
 * The full-sized chemistry lab they carry around with them also qualifies.
 * Also the "Wrapped up in a nice little boxinator" literally compacts his WHOLE BUILDING into a tiny box.
 * Improbable Age: Lampshading it is a Running Gag in the series.

Phineas: Yes, yes I am."

"Baljeet: I do not even know why you even brought the swordfish!
 * Improbable Aiming Skills: Ferb. In "Ain't No Kiddie Ride", Ferb uses a slingshot to shoot a quarter into the quarter slot of the former children's ride (currently modified to be a working rocket) that Candace was at that moment falling to her doom in.
 * Improbable Parking Skills: In "Bubble Boys", Candace channels Elwood Blues to pull off a 90-degree Parallel Parking job with her right foot on the dashboard in her mother's temporarily-rocket-powered station wagon.
 * Improbable Weapon User: Doofenshmirtz is surprisingly adept with a bratwurst.
 * Wait, what?
 * And in "Raging Bully", Doof and Perry weaponize birthday hats, party noisemakers, paddle-balls...
 * In "Brain Drain", Isabella uses her sash as a weapon in a fighting game featuring themselves to defeat Buford.
 * In a World: Parodied and tributed to the late Don LaFontaine in "The Chronicles of Meap"
 * Incredible Shrinking Man: "Hide and Seek" is based on this.
 * Incredibly Lame Fun: "Phineas and Ferb Interrupted".
 * Indulgent Fantasy Segue: Candace has one at the beginning of "Out to Launch".
 * Ineffectual Sympathetic Villain: On the few episodes Perry is otherwise occupied, Doofenshmirtz tends to defeat himself one way or another.
 * Informed Ability: It's become a recurring gag that Ferb apparently gives several long speeches off-screen that only Phineas seems to hear (except once in "Finding Mary McGuffin", when it's a random bystander he's interrogating). We do finally get one in "The Lizard Whisperer" though.
 * Buford being a bully.
 * Informed Attractiveness: Invoked as a joke in "Quetest Day Ever". Doofenshmirtz accidentally turns himself handsome using on of his inators in the episode "The Quietest Day Ever". Yes, he is certainly an improvement from how he was before, but the population of Danville oversells it way, way too hard.
 * Informed Flaw: Doofenshmirtz's ineptitude is a running gag; the writers often remind us that he purchased his doctorate online. In truth, he single-handedly creates the most powerful inventions in the series. Phineas and Ferb can push the laws of physics (defying gravity for short times, repairing an old time machine, etc.), but Doof can do things that border on magic (creating or destroying matter, opening portals to other dimensions, altering abstract concepts like ugliness or love, and even turning metal into broccoli). Doof may not have a real doctorate, but he is legitimately brilliant.
 * Especially shown in "Oil on Candace", where Doofenshmirtz is showing off his career of evil to his old teacher. When asked whether his -inators actually worked, Doof sheepishly "admits" that they didn't, even though anyone who watched the episodes they appeared in would know that they actually worked just fine. The only part of that sequence that was accurate was that the Drillinator did indeed fail to harm anyone other than Doofenshmirtz himself.
 * In "Oh, There You Are Perry", Phineas uses giant speakers to call for Perry. All the platypuses in Danville end up in their backyard, and there's a surprising amount of them. Phineas and Ferb then look at them one by one to determine if they're Perry, and Phineas criticizes flaws that each platypus has like 'too tangerine' that makes it different from Perry despite the fact each platypus is identical.
 * Ink Suit Actor: Coltrane, voiced by Corbin Bleu.
 * The creators actually changed his standard outfit (something that they never do) between his first appearance and "The Baljeatles" to match Corbin.
 * Also, quite a few guest stars have been in one of these.
 * Inelegant Blubbering: Buford, of all people, is crying in this fashion during almost the entity of "Voyage to the Bottom of Buford".
 * There are exceptions, but if you ever see Candace crying, expect it to be in this manner.
 * Inexplicably Awesome: Ferb. He can teleport, speak several languages, including Martian, can knock you out with one Vulcan-based nerve pinch, and is able to build anything the plot requires. Why? Nobody knows.
 * Innocent Prodigy: The titular brothers, both of whom are creative and technical geniuses, but use their talents more for their own amusement than anything else. They also manage to regularly figure out the solutions to other characters' problems, while still maintaining an oddly childlike sense of naivete.
 * At least Once an Episode, somebody will ask Phineas if he and Ferb are too young to be doing whatever they're doing. Phineas always responds: "Yes, yes we are."
 * Innocent Innuendo: Perry shaving Doofenshmirtz in "The Remains of the Platypus". See for yourself.
 * Insane Troll Logic: One episode involves Doofenshmirtz charting out the pattern of evil within a month. He discovers that while his own evil is perfectly constant, there is a gigantic increase in general evil around the time of the full Moon... assuming that the problem is Werewolves. He considers this bad because it makes him seem less evil by comparison and reasons that he should rotate the Moon so the dark side always faces the Earth. When he later discovers that the light of the Moon is actually a reflection of the light of the Sun, he reasons that he should have instead rotated the Sun.
 * Doof pulls this off a lot, actually...
 * As does Candace, on occasion. Remember her imagination spot about asking Jeremy to the dance in "Out to Launch"?
 * Insistent Terminology: From "Last Train to Bustville":

Buford: It's a marlin."

"Doofenshmirtz: A-ha, Perry the Platypus! Your giant, robot dragon is no match for my giant, robot, ah... Queen Elizabeth... the First..."
 * It's not a party, it's an intimate get together!
 * CANDACE PARTY! CANDACE PARTY!
 * Instant Awesome, Just Add Mecha: If by "awesome" you mean "hilarity", Norm is your guy.
 * TREEHOUSE ROBOT FIGHT!

"Candace: Oh, that's ridiculous! I do not have wheels!"
 * Ironically when he switchs robots with Perry it turns out the Queen Elizabeth I mech was more powerful.
 * Intentional Engrish for Funny: Used in the Caramelldansen Vid song.
 * Candace's doppelganger, Princess Baldegrunde in "Make Play".
 * Interactive Narrator: During the song "Lunar Taste Sensation", the singer blames Baljeet for forgetting the marshmallows. Baljeet and the singer named Disembodied Reggae Space Voice proceed to get into an argument.
 * Interquel: "Isabella and the Temple of Sap" takes place during "Bubble Boys".
 * Intrepid Reporter: Isabella becomes one in "The Beak". She even refers to herself as one with those exact words.
 * In the Local Tongue: A French fashion designer tries to flatter the long-necked Candace into modeling for him by calling her his cou de crayon, which Ferb points out means "pencil neck."
 * Inventional Wisdom: Many of Doofenshmirtz's inventions fall into this trope.
 * The Intern: Carl.
 * He's even got his own song!
 * Interspecies Romance: One of Doof's girlfriend's left him for a whale. She was last seen living in his mouth, cooking him pancakes.
 * In the "Chronicles of Meap" in-character commentary, when Candace's Senor Frowg appears and she says "I just found out why cows and frogs don't date", Major Monogram says that Agent C and Agent F have been an item for some time.
 * Invisible Backup Band: Lampshaded. See Musical Episode below.
 * I Owe You My Life: "The Bully Code". The song lampshades it as "a Seventies sitcom cliché."
 * I Take Offense to That Last One: A visual version comes up in "Greece Lightning"; Phineas mentions they've made a chariot for Candace that looks just like her... and is actually a repulsive gorgon. Candace's response?

"Candace: (After watching a literal Clip Show of these) ...What the heck was that?
 * I Think You Broke Him: Mandy's reaction to Thaddeus and Thor getting stunned stupid by Phineas and Ferb's fort: "Nice going! You broke their brains."
 * It Is Always Spring: Or rather, it's always summer.
 * Except when it's S'winter, in which case, it's winter and summer together.
 * Some people call it 'Wummer'.
 * Or S'Fall, which is fall and summer together.
 * The Christmas Special takes place at... well, when do you think? It's canonically set after the other episodes that have aired so far.
 * It Makes Sense in Context: Too many examples to list, but a particularly disgusting example would be the "triple scoop garlic-roach cone". Bleh...
 * One hilariously Lampshaded example from "Phineas's Birthday Clip-o-Rama!"

Baljeet: That is what I said! Sure, give the weird stuff to Baljeet, who cares if it does not work out of context!"

"Candace: What about my needs?"
 * They had one entire episode that hilariously played with this. To give you a hint, imagine Doofenshmirtz Evil Incorporated's interior, Doof's Inator is flashing yellow and red lightning, Carl is dressed in a squirrel suit and trapped in a cage, Perry the Platypus is Doof's Butler, Doof himself is in his briefs (yes, just his briefs), celebrating because he feels he has finally won, Major Monogram is wearing jeans and a Hawaiian style button-up shirt, bloated, and tottering out of Phineas an Ferb's backyard, scaring everyone away, an here's the kicker: one of Phineas and Ferb's inventions crashes through the roof of DEI, and opens up to reveal four British Bobbys and a midget, who then proceed to take the party up to an eleven.
 * It Runs On Nonsensoleum: And proud of it!
 * It's All About Me: Candace plays this trope to perfection. If she has to decide whether to hang out with friends and/or family, including her boyfriend Jeremy, or carry out her ill-advised, obviously pointless and arguably spiteful self-appointed mission to bust her brothers, she will choose the latter every single time.
 * That said, the beginning of "Candace's Big Day" is the one that really takes the cake: Candace criticizes her aunt's marriage plans simply because they don't involve her. Even her own mother practically calls her out on that one.

"Major Monogram: [Doofenshmirtz] has been quiet recently. A little too quiet. I want you to find out what's not going on and ... er, put a stop to it."
 * It's Quiet... Too Quiet: Whenever Candace enjoys one of the boys' inventions and doesn't call Linda, she starts to get concerned and, ironically, returns immediately.

"Candace: How did you get a one-hit single?!
 * It Was Here, I Swear: Candace embodies this trope.
 * Heck, most of the series embodies this trope.
 * A good half of the boy's projects are simply removed from sight, with no evidence as to where they actually end up. Notably, "Don't Even Blink" is spent specifically trying to find out what keeps happening to them.
 * There are a number of times where Linda does see the boy's project. However, during these instances, there is either no evidence connecting them to the boys:
 * "Put That Putter Away", where the boys' mini-golf course was dropped on top of Little Duffers, leading Linda to think they simply remodeled the place.
 * The device from "The Bully Code", which she just thinks is public art.
 * "Dude, We're Getting the Band Back Together!", which she believes was arranged by Lawrence.
 * Or she only sees them after something happens to make them appear normal:
 * "Thaddeus and Thor", where Linda only sees the top, "old-school construction" portion of the boys's fort.
 * "Hip Hip Parade", where the giant floats Phineas and Ferb create float away, leaving Linda to see only them and their friends pulling kiddy wagons behind them.
 * "Interview With a Platypus", where Linda sees the animal translator the boys build, but she only sees them use it to decipher Perry's chatter, which turns out to not mean anything, so she has no reason to think that it actually works.
 * Mom's Birthday revolves around the boys giving over-the-top gifts to Mom, with Candace trying to keep up. She makes no comment about the big screen TV and stage in her backyard.
 * It Wasn't Easy: How Phineas explains his and his friends' sudden popularity in "Flop Starz":

Phineas: Well, it wasn't easy. It took most of the morning and half a dozen phone calls!"