User blog comment:Bowl108/Phineas and Ferb on Extreme Makeover/@comment-961279-20110522151353/@comment-181516-20110522213646

I remember seeing the summary on wikipedia and it said that several cartoon characters like spongebob, the muppets and Phineas and Ferb were going to be featured as guest characters. That might have been where he saw that phineas and ferb were in the episode.