Phineas and Ferb Christmas Vacation!, on Disney XD & Disney Channel
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This is based on the series Phineas and Ferb. On Christmas Eve, the boys decide to decorate Danville as a giant Christmas card thanking Santa Claus for all he does for people. Meanwhile, Candace is worried about what to get Jeremy for Christmas. And Dr. Doofenshmirtz is upset because he doesn't hate Christmas; he's totally apathetic toward it. Still, he feels an evil scientist should hate Christmas, and wants to find a reason to ruin it. He finally does find his reason, and turns on a machine that's designed to make everyone in the Tri-State area show up as naughty on Santa's list. Once that happens, Phineas and Ferb have to deliver presents to everyone in Danville themselves (with the help of a couple of elves, as well as their usual gang of friends).

Well... the show is always amazing in how it manages to connect all the different plot points, even if the characters themselves are completely unaware of the different plotlines that are going on. And as usual, everything is connected in this special. But the cool thing is, in the end, it turns out that this time, there was someone behind everything that happened and how it all tied together, though I won't say who. But I will say, everyone got what they wanted for Christmas. And also, of course, there are several fun musical numbers. And allusions to other Christmas specials, though the most obvious was the close plot similarity to Twas the Night Before Christmas. Anyway, dunno what else to say, but.... as always, it was all really clever and amusing and fun. This special is available on the DVD "A Very Perry Christmas," along with several other (non-Christmas) episodes of the series.