Phineas and Ferb is the cleverest cartoon series since the great Warner Bros. shorts of the mid-20th century. The titular characters are step-brothers who — well, it never sounds as good when you explain it — but every episode they invent and build some amazing thing that inevitably disappears by the end of the day.  Meanwhile, in a subplot to every episode, their pet, Perry the Platypus, has an alter ego life where he is known as Agent P, fighting evil, almost always in the form of his arch nemesis Dr. Doofenshmirtz, whose goal is to take over the tri-state area. This is Perry in his pet form. You can tell because when he is acting as Agent P he wears a fedora.

Like I said, no short explanation can do it justice. But if you’re interested, you can find it all over the Disney channel.