When Sylvester hears that a children's museum's prize exhibit is Tweety Pie, he tires to raid the museum in order to have lunch. He doesn't succeed in his mission, due to Tweety's smartness, and the children.

When Dr. Doofenshmirtz's latest invention causes the Marvel heroes to lose their powers, they team up with Phineas and Ferb to save the world from Doofenshmirtz and the Marvel villains.

Phineas and Ferb get trapped in an alternate dimension where the evil Doofenshmirtz rules the tri-state area. They must find a way back home with the help of their pet platypus named Perry, who they discover is a secret agent.