In imperial China, Doofus Khan tries to take over the Tri-Province Area by abducting Princess Isabella, and Phineas, Ferb and the gang must learn to become warriors by Master Perry to take him down. During this, Candace spies on the gang and tries to bust them for inventing things whose technology is far too advanced than what they have today.
Tropes:
- Anachronism Stew: Lampshaded multiple times; the Candace of this timeline is trying to bust her brothers for their big ideas because the technology they use to make them is way ahead of its time.
- Arbitrary Skepticism: When the kids meet Master Perry:Buford: I can't believe he's a platypus!
Baljeet: Phineas pulled a jou with giant mechanical feet out of his backpack and that is what bugs you?! - Art Shift: The background art of this episode emulates Chinese paintings, with the mists of the water represented by swirls. In fact, this episode won a Primetime Emmy® for background painter Jill Daniels for Outstanding Individual in Animation for this episode.
- Artistic License – History: The Great Wall of China was actually built over 1500 years before this episode took place, between 50 and 15 B.C.E. Also, elderly Phineas mentions mahjong, which won't be invented for another three centuries.
- Bald Head of Toughness: Turns out all the gang, with the exception of Baljeet, are bald underneath their dǒulìs.
- Behemoth Battle: Doofus Khan's robotic dragon takes on Phineas and the gang's giant terracotta warrior.Regent Monogram: Man, they would love this in Japan.
- Booby Trap: Doofus Khan's stairway is lined with booby traps that he claims only he knows how to get around, but it turns out, he has completely forgotten where the booby traps are. Phineas and Ferb easily evade them, and slide down the bannister with Princess Isabella.
- Clutching Hand Trap: General Carl uses a giant Chinese finger trap to cuff Doofus Khan.
- Copycat Mockery: When following the gang, Candace mocks what Baljeet just said.Baljeet: Look, a Chinese eviscerating fish. Though I suppose here in China we just call them eviscerating fish.
Candace: (mockingly) "Oh, but here we just call them eviscerating..." (falls into the river) - Creator Cameo: In the epilogue, the older version of Phineas is actually voiced by director Robert F. Hughes.
- Damsel in Distress: Princess Isabella gets kidnapped and held for ransom by Doofus Khan, who has the intent of making Regent Monogram too helpless to prevent Doofus Khan from taking over the Tri-Province Area.
- Department of Redundancy Department: The Unclimbable Mountain of Unclimbableness and the Uncrossable River of Uncrossableness, both of which were named by the Redundant Scribe of Redundantness. Candace calls the mountain the "Stupid Mountain of Stupidness" and the scribe says that's how he originally intended to call it. The scribe also speaks redundantly whenever he greets someone or apologizes to someone."Oops, my bad, sorry, my apologizes, mea culpa!"
- Duck!: When Regent Monogram tells General Carl to duck, Carl assumes Monogram mistook Doofus Khan's wind-up dragon for a duck and ends up getting hit by the dragon's tail.
- Elseworld: The episode takes place in a world where the characters live in imperial China.
- Flashback: Parodied. Perry attempts to use one to explain why he retired... but nobody else, including the audience, can actually see the flashback, so Perry just stands there rippling for a while while everyone else stands there confused. Buford also attempts this as it appears he is about to regale how they took on an entire army, but Phineas informs him there is no time for a flashback.Buford: What flashback? I'm just rippling. It relaxes me.
- Historical AU: The contemporary-era characters are transplanted into imperial China.
- I'm Okay!: One of the members of Doofus Khan's army says this after Phineas is impressed with Buford and Baljeet taking them all down.
- Mooning: During the song "The Way of the Platypus", Buford moons the audience to show he has no beaver tail. Fortunately for the viewer, Perry the Platypus quickly covers it with a fan.
- No, You:Regent Monogram: You barbarian!
Doofus Khan: I know I am, but what are you! - Noodle Implements: It's not shown how Phineas and Ferb get past Doofus Khan's traps, but a comment from Phineas suggests that a yak bladder was needed at some point.
- Offscreen Moment of Awesome: While Phineas and Ferb rescue Isabella, Buford and Baljeet manage to beat off all of Doofus Khan's mooks.
- Old Master/Retired Badass: Perry is one in this reality. We never learn why he retired; Perry attempts to show them with a flashback, but none of the kids are able to see it.
- Regional Riff: The Evil Jingle ("Doofus Khan's multi-level yurt") is set to the Oriental Riff.
- Related Differently in the Adaptation: Implied. The Candace of this timeline never once interacts with Phineas and Ferb nor calls them "brothers". In addition, Phineas and Ferb never interact with Linda and Lawrence, nor do they refer to them as "mom" and "dad", only Candace does, hinting that the boys could be unrelated to them.
- Related in the Adaptation: Princess Isabella is under the care of Regent Monogram; in the main series Monogram and Isabella haven't met.
- Ship Tease: This version of Phineas appears to have a bit of a crush on Princess Isabella.
- Shout-Out:
- One of the things done during "Way of the Platypus" is "Fly to a swamp planet, meet a little green man / And move big, heavy things with your mind!"
- "Way of the Platypus" ends with the gang freezing in a fighting stance and that shot dissolving into a painting.
- Skyward Scream: Baljeet does this at one point during "Way of the Platypus", which is lampshaded by the lyrics.At some point you'll drop to your knees when it's raining
And look up into the skyyyyyy! - Squick: In-universe. Princess Isabella is disgusted by an unsavory feature of Doofus Khan's robotic dragon.Princess Isabella: Ew, who puts armpit air on a mechanical dragon?
- Stalker Shot: For every location the boys pass, Candace then comes to the same location spying on their mission.
- Suspiciously Specific Denial: When Regent Monogram asks about Princess Isabella's whereabouts, Doofus Khan explains that she certainly didn't escape and thus force him to alter his plans.
- That Poor Cat: Heard during the booby trap sequence.
- Tempting Fate: When Doofus Khan neutralizes the kids' wind-up terracota warrior by removing its key, they try to do the same to his wind-up dragon but can't find the dragon's key. After Doofus Khan says that only a great master and warrior can know where he has hidden his key, Master Perry the Platypus shows up.
- Time-Shifted Actor: As stated under Creator Cameo, the elderly version of Phineas is voiced by director Robert F. Hughes. Averted with Ferb whose one line is still voiced by Thomas Brodie-Sangster.
- Time Skip: After Doofus Khan is defeated, Phineas and Ferb decide to use the rubble from the destroyed mechs to build a Great Wall to prevent future invaders from entering the Tri-Province Area. The next scene is from 40 years later, when they finish building it.
- Training Montage: Master Perry puts Phineas, Ferb, Buford, and Baljeet through one set to "Way of the Platypus".
