Disney is getting serious about "Phineas & Ferb," the animated TV show about a couple of brilliantly outlandish school kids.

The show, on both the Disney Channel and Disney XD, not only got picked up for a third season, but a Christmas special and a music CD is in the works.

Disney ordered 35 more episodes, which will take the show to 100 total episodes. The third season also features a new recurring cast member: Jack McBrayer, the actor who plays Kenneth the page on "30 Rock."

"Phineas & Ferb," which also stars Ashley Tisdale, is about a couple of stepbrothers who spend their 104-day summer vacation masterminding one grandiose scheme after another. Tisdale plays the boy's sister, Candace, whose mission is to tattle on her precocious little brothers.

Co-created by Dan Povenmire and Jeff "Swampy" Marsh, it's the top-rated primetime animated show for children 6-11 and 9-14.

Disney Channel entertainment president Gary Marsh hinted during the Licensing International Expo in Las Vegas recently that bigger things were in store for the property.

"I am telling you all now, 'Phineas & Ferb' is going to be our next worldwide sensation," he said.