Phineas and Ferb

Tree to Get Ready 

Guest starring is John O'Hurley ("Seinfeld," "Dancing with the Stars") as Dr. Doofenshmirtz's brother Roger. Phineas and Ferb decide to build the ultimate tree house, and convince Candace to let them construct one for her too. Her brothers' antics catch her ... moreoff guard, but she eventually finds herself having fun. Meanwhile, Dr. Doofenshmirtz has a plan to unleash pigeons over City Hall, with hopes of ruining the ceremony in which his brother Roger is to receive a key to the city, on "Phineas and Ferb."

Vote for your favorite "Phineas and Ferb" musical number at DisneyXD.com and DisneyChannel.com.

"Phineas and Ferb's Musical Cliptastic Countdown" airs Monday, Oct. 12, at 8 p.m. ET/PT on Disney XD.
"Phineas and Ferb" airs on Disney Channel and Disney XD.

(Disney Channel)