Doofenshmirtz and Perry's relationship

Doofenshmirtz and Perry have a very strange relationship. Though they claim to be enemies, they are also nice to each other alot.

Doofenhsmirtz's Opinion of Perry
Doofenshmirtz thinks of Perry as a 'suave, semi-aquatic personification of unstoppable, dynamic fury'. (Oil on Candace)

While Doing Evil
He revealed that he feels lonely when Perry doesn't come. (2009 Radio Disney premiere) He is often offenended if Perry is late, or leaves early (No More Bunny Business) (I Was A Middle-Aged Robot). Even though he preffers Perry to come, he still gets frustarated when Perry defeats him (Phineas and Ferb series). His catch phrase is "Curse You Perry the Platypus!", though it is often not said/changed.

During the events of It's About Time!
In the episode It's About Time, Dr. Doofenshmirtz wants to take a break and fight another nemesis. This leaves Perry depressed, even though Heinz claims "he still hates him". At the end of the episode, Perry, Heinz, and Peter go on the show, Dr. Feelbetter. During the show, Dr. Doofenshmirtz says sorry for replacing him, and asks if Perry can be his nemisis again. Perry turns nice, and then they have another battle.

While Not Doing Evil
When Dr. Doofenshmirtz sees Perry with out his hat, he doesn't reconize him (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. But when his date comes, he needs Perry to act like a pet, since his date didn't know he had a nemisis. Strangely, the date adores Perry more than Heinz. In Chez Platypus, Dr. Doofenshmirtz started out with a scheme to destroy love, but got distracted with his new girlfriend. He was in love so much, he let Perry foil his plane and destroy his de-love-inator satellite.

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

While Stopping Evil
Perry is very serious when he fights Doofenshmitz. Even though Heinz's plans always fail, he still thinks that Doofensmitz is evil (Oil on Candace). Perry is often unimpressed about Heinz not noticing him in his disguises (Flop Starz). Perry always gets trapped by Doofenshmirtz, too.

During the events of It's About Time!
In the episode, It's About Time, Doofensmitz gets another nemisis, leaving Perry sad and depressed. This episode reveals that he hates Perry, but in a friednly way. This also reveals that Perry enjoys defeating Doofensmirtz, and vice versa. They become nemisises again at the end of the episodes, and also had a battle.