Doofenshmirtz and Perry's relationship

Doofenshmirtz and Perry have a very strange relationship. They claim to be enemies, but they are relatively civil to one another more often than one would think they should be.

Doofenshmirtz 's Opinion of Perry
Doofenshmirtz thinks of Perry as a 'suave, semi-aquatic personification of unstoppable, dynamic fury'; he says so in a letter to his former professor (Oil on Candace). He even once admitted that Perry was his best friend. ("The Chronicles of Meap").

While Doing Evil
Doofenshmirtz has revealed that he feels lonely when Perry doesn't come to defeat him. (2009 Radio Disney premiere) He is often offended if Perry is late or leaves early ("No More Bunny Business"), ("I Was A Middle-Aged Robot"). He is usually injured in some way - or at the very least his inventions are destroyed - each day when Perry comes to defeat him (though on some occasions he receives no comeuppance, at which times he wonders why he feels "so empty") ("Hide and Seek"). Although he prefers Perry coming to Perry not coming, he is still infuriated when Perry defeats him (Phineas and Ferb series).

His catchphrase is "Curse you, Perry the Platypus!", though it is sometimes not said or humorously altered (ex. Phineas: "Bless you, Perry the Platypus!" in Hail Doofania!; Doofenshmirtz: "Curse you, Peter the Panda!" in It's About Time!). He generally says it after Perry has defeated him.

In the beginning of the summer, Perry entered Doofenshmirtz Evil Inc. by breaking through walls or doors or the ceiling. One time, Doofenshmirtz actually made him pay for a door ("Lights, Candace, Action!"). Eventually, Doofenshmirtz actually gave Agent P a key to the apartment to save it from destruction ("I, Brobot").

During the events of It's About Time!
In the episode "It's About Time!," Dr. Doofenshmirtz gets another nemesis. Their "breakup" leaves Perry sad and depressed, even though Heinz claims he still hates him. Agent P remniscises about his daily battles with Doofenshmirtz, and eventually it comes to the point where he turns in his hat to the Agency. Doofenshmirtz, it seems, missed him too, as when he sees a picture that reminds him of the very first day he found out he had Perry the Platypus as his nemesis, he arranges that Peter, Perry, and himself go on the show, Dr. Feelbetter, to sort everything out. During the show, Dr. Doofenshmirtz says he is sorry for replacing him, and asks if Perry can be his nemesis again. Perry replies by putting on his agent hat and they become nemeses once more. They almost immediately reinforce the bond with another battle.

This episode reveals that Doofenshmirtz hates Perry, but in a "friendly" way, similar to a "frenemy" relationship. Perry, in return, enjoys hating and defeating Doofenshmirtz. He cannot seem to function without this constant in his life.

While Not Doing Evil
When Dr. Doofenshmirtz sees Perry without his hat, he doesn't recognize him. One time Doofenshmirtz did not recognize him even though he had his hat on, due to the fact that he was also wearing a plumber's utitilty belt. ("Lawn Gnome Beach Party of Terror"), ("Vanessassary Roughness"), ("She's the Mayor") ("The Lemonade Stand").

In "Get That Bigfoot Outa My Face!", Perry goes to Doofenshmirtz 's hideout in the woods, only to find out it is Heinz's week off. When his date comes, he tells Perry that he needs him to act like a pet, since his date didn't know he had a nemesis. Strangely, the date adores Perry much, much more than she does Heinz, which makes Heinz a little jealous of Perry.

In "Chez Platypus", Dr. Doofenshmirtz started out with a scheme to destroy love if his date would fail, but when his date turned out great, he let Perry foil his plan and destroy his De-Love-inator satellite.

,There have been multiple occasions when Perry has helped Doofensmirtz with something if he deems it to be not evil; examples include when he helped Doofenshmirtz set up a birthday party for his daughter Vanessa, when he shopped for groceries with Doofenshmirtz, and when he helped Doofenshmirtz learn how to kick a ball ("Dude, We're Getting the Band Back Together"), ("Unfair Science Fair Redux (Another Story)"), ("Thaddeus and Thor").

It seems that even if Doofenshmirtz isn't doing any evil when Perry shows up, he still feels compelled to trap him ("Voyage to the Bottom of Buford"), ("Tip of the Day"), ("Finding Mary McGuffin"), ("Put That Putter Away").

Without Perry, though, Doofenshmirtz cannot function correctly. As the show progresses, so does Doofenshmirtz's relationship with Perry.

Perry's Opinion of Dr. Doofenshmirtz
Perry is Dr. Doofenshmirtz 's nemesis, and part of the O.W.C.A.

While Stopping Evil
Perry is very serious about his job and when he fights Doofenshmirtz. Even though Heinz's plans always fail (thanks to Agent P's intervention) he still thinks that Doofenshmirtz is evil. He reassured Doofensmirtz that he was indeed evil once when Doofenshmirtz himself was feeling unsure of his own evil qualities ("Oil on Candace").

Perry is generally unimpressed with Heinz in general, from his overly-dramatic ways to his inability to recognize Perry in various disguises.

Perry does, however, save Dr. Doofenshmirtz's life whenever he needs it ("The Magnificent Few"), ("The Chronicles of Meap"), ("Spa Day"). It is unclear if this is because he doesn't want his nemesis to perish or because it is against his conscience as a "good guy".

Generally, Perry gets sent out to defeat Doofenshmirtz, and when he arrives on the scene, he is trapped. Doofenshmirtz then explains to him his evil scheme of the day, sometimes accompanied by a backstory depicting an event in his childhood that scarred him for life and turned him into what he is today. Perry finds a way to escape the trap and proceeds to defeat Doofenshmirtz.