Phineas And Ferb: Season 2, Episode 17

2 - 17: Oh, There You Are, Perry

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.