Mom's In the House When Phineas and Ferb can't find Perry, they decide to create the Perrytronic 3000, a mechanical structure that can assume any form. Of course, being aware of the boys' every move, Candace decides to take a different tactic on her busting approach by using a new technique that keeps Phineas and Ferb from finishing their Perry project. Meanwhile, Doofenshmirtz invents a "Duplicator-Inator 2" so that he can duplicate his own head and supposedly make himself twice as smart.