Misperceived Monotreme

Sorry to be so harsh Agent P, but today is a very special day: Your one-hundredth battle with Dr. Doofenshmirz!

Perry misses his 100th battle against Dr. Doofenshmirtz when Candace takes him to the Charity Pet Wash with her. Perry's absence goes unnoticed when the zookeeper's typical platypus at the Danville Zoo stops Dr. Doofenshmirtz's plan to zap his brother with his "Least Likely-inator." Meanwhile, the boys build a fun house Phineas and Ferb style.

Episode Summary
During a report about the zoos latest new animal, a platypus, two guys were loading sandwiches into their truck but the platypus that also like sandwiches and climbed in the loading truck. Meanwhile, Phineas and Ferb are thinking about making a fun house in the house and Candace gets a call from Jeremy. He was hosting a charity pet wash. When Jeremy is talking about how a person's personality can be told by how they treat a pet, she took Perry to the pet wash. At headquarters, Monogram and Carl prepare for the 100th battle for Agent P. When dumping out all the stuff for the fun house, the platypus got out and entered Perry's lair. Mistaking it for the real deal, the platypus does Perry's job. At the pet wash, Perry tries to avoid getting bathed but failed. At Doofenshmirtz Evil Inc., the battle begins. Doof created a Least Likely-inator. On the side note, Irving got hit by it and tries to flirt with Isabella. The battle starts with the platypus getting out of the trap and lick up Doof's coffee. Then he crushes Doof with a sandwich stand. The sandwiches scatter on the Doctor's devices and then got slammed into a brick wall. Perry is done bathing in the water and is on the way home. After exploring the fun house, Doof shot the Least Likely-inator on Candace and exploded. Candace cleaned the whole thing up unintentionally before Linda got home. Meanwhile, the fake Perry leaft the lab and the real Perry arrived. Monogram and Carl congratulated him despite not fighting at all.

Songs

 * Quirky Worky Song
 * Livin' in a Funhouse

End Credits

 * Last verse of Livin' in a Funhouse

Whatcha doin'?
None.

Perry's entrance to his lair
Carl tests all the secret agent doors to see if any of them are jammed (Perry was late for his mission). The zoo platypus smells Carl's sandwich and instinctively walks into the tree elevator as it opens.

Evil Jingle
Doofenshmirtz Evil Incorporated!

Background Information

 * It is unknown if Carl, Monogram, and Dr. Doofenshmirtz found out that Perry never had his 100th battle with Doofenshmirtz.
 * This is the first season three episode to have more than one song.
 * First time Jenny appears without Stacy.
 * It is revealed that Doofenshmirtz's father is alive.
 * When Irving is hit with Dr. Doofenshmirtz's invention, he thinks that Phineas and Ferb's inventions are lame and he hits on Isabella.
 * If you look carefully when the platypus pushes the sandwich stand, he was on his hind legs like Perry, and his eyes were focused.
 * This episode reveals that Perry might hate baths. However, it's also possible he just wanted to escape and go fight Doofenshmirtz as quick as possible.
 * The logo to the O.W.C.A has finally been revealed in this episode.O.W.C.A.jpg
 * The "Marsh" maneuver was most likely named after Jeff "Swampy" Marsh the creator of the show.
 * This is the first episode that Phineas and Ferb's invention is cleaned up by Candace.

Errors

 * Along with Ask a Foolish Question, most of the multiple line closed captions must be read from bottom to top instead of top to bottom.
 * After Candace takes Perry out of the water and said, "Here's cuteness!" there was a patch in the grass that seemed to be not colored in.
 * It's unknown why Major Monogram, Carl, and Doofenshmirtz were unable to tell the difference between Perry and the Platypus that escaped from the Zoo.
 * When Candace picked Perry up whilst he was using his watch, in the next scene, the watch is gone.
 * In the opening scenes at the house, Perry dosent have his top hairs, but while Candace is calling Jeremy, he has his top hairs again.
 * This is actually Perry's 118th battle with Doofenshmirtz (according to the list of episodes up to this point). we can also mention here that the christmas vacation happens in the future, also the Quantum Boogaloo, they hadn't fight in Isabella and the temple of Sap, and perhaps the events of Unfair Science Fair Redux, count as the battle of Unfair Science Fair, they hadn't fight in Hail Doofania, No more Bunny Business, I Was a Middle Age Robot, Undercover Carl also remember that in The monster of Phineas and Ferbenstein they didn't fight, and Phineas and Ferb get Busted and Wizard of Odd were dreams, they hadn't fight in and It's About time, Perry lays an egg, Thaddeus and Thor, which make a total of: 105 battles.
 * However, creators Dan Povenmire and Jeff "Swampy" Marsh confirmed the episodes don't take place right after the previous, indicating this is the 100th day of summer if Perry started fighting Doofenshmirtz since Rollercoaster.
 * The mirror in the clip the O.W.C.A recorded was just triangles and a bit of Doofenshmirtz's hand and brush.

Continuity

 * Fourth time someone other than Perry goes to fight Doofenshmirtz. The first was Peter the Panda in "It's About Time!", the second time was Planty the Potted Plant from "No More Bunny Business" and the third time was the Dodo Bird From "Last Train to Bustville".
 * Third time Perry doesn't interact with Dr. Doofenshmirtz. First is in "No More Bunny Business" and the second is in "Undercover Carl".
 * Second time Perry is referred to as a monotreme. ("Swiss Family Phineas")
 * The giant floating baby head is shown again.
 * This is also the 3rd or at least time the guy with the name Steve is shown ("The Lizard Whisperer")
 * Ticks and tocks are heard again ("Don't Even Blink", "Make Play", "Unfair Science Fair Redux (Another Story)").
 * Second time another platypus besides Perry is shown, though this time he is distinguishable from Perry, though only by his nose when he is smelling and his eyes, which are red. ("Oh, There You Are, Perry")
 * While Phineas is talking to Perry, the reporter can be heard telling the zookeeper that she had made the word "platypus" up, and then she said, "No, it's a real word." This is similar to a conversation Candace and Stacy had in an earlier episode (Gaming the System).

Allusions

 * When Doofenshmirtz hits the brick wall, Monogram calls it the "Marsh Manuever". This is a reference to his voice actor, Jeff "Swampy" Marsh.

Cast

 * Vincent Martella as Phineas
 * Ashley Tisdale as Candace
 * Thomas Sangster as Ferb
 * Caroline Rhea as Mom
 * Mitchel Musso as Jeremy
 * Dan Povenmire as Dr. Doofenshmirtz
 * Jeff "Swampy" Marsh as Major Monogram
 * Dee Bradley Baker as Perry
 * Bobby Gaylor as Buford
 * Jack McBrayer as Irving
 * Lisa Ling as Zookeeper (Takira Quawck )
 * Alyson Stoner as Isabella