(the second half of S1E1) specifically features the family celebrating Candace’s birthday at Mount Rushmore, where Phineas and Ferb attempt to carve her face into the mountain as a "helpful" gift, while Candace nearly loses her mind trying to expose them.
: Candace initiates her endless quest to "bust" her brothers by trying to show their mother, Linda, the massive coaster. [S1E1] Rollercoaster/Candace Loses Her Head
: The invention conveniently vanishes just as Linda arrives, a staple "helpful" plot device usually caused by Dr. Doofensmirtz's antics. (the second half of S1E1) specifically features the
: Perry the Platypus sneaks off to his secret lair to receive a mission from Major Monogram, marking the first time he foils Dr. Doofensmirtz's "Inator." Doofensmirtz's antics
In the pilot episode of Phineas and Ferb , several "helpful" recurring features and tropes of the series are established:
: Phineas and Ferb begin their summer by building a logic-defying rollercoaster in their backyard, setting the "big project" template for the series.
: This episode introduces Phineas’s iconic catchphrase when he notices Perry has disappeared.