When Phineas and Ferb get inspired by Candace's dessert club to create the biggest piece of gelatin ever, even Jenny and Stacy want to join in. Meanwhile, Doofenshmirtz has a horrific plan, to turn Perry evil!

Perry the Platypus is reassigned and forced to move to the Quad State area with a new family and battle a new villain, the Regurgitator. During his new assignment, Phineas, Ferb, and Candace put in every effort to find him, hoping he'll return to them.

Phineas and Ferb are decorating their city for the arrival of Santa Claus. But when the evil mad scientist Dr. Heinz Doofenshmirtz uses a machine to ruin the holiday, Phineas and Ferb must find a way to fix it and save Christmas.