Phineas and Ferb are brothers from the Disney TV cartoon of the same name.
Figure Eight- Isabella is featured in the song & Phineas has a cameo.
Elbow Room- Phineas, Ferb, Perry the Platypus & the Phinidroids & Ferbots are featured in the song.
Verb: Thats Whats Happening- Phineas appears as the boy, Perry appears as Verb & Linda Flynn (PnF's mom) apperas as the boys mom.
Telegraph Line- Phineas, Ferb, Dr. Doofenshmirtz, Stacy Hirano & Perry appear in the song.