This is fun. When someone says "Christmas" you may not be inclined to think of Harry Potter immediately. But the holiday has featured pretty prominently in the books (c'mon, the invisibility cloak was pretty much the best present ever), so why not a little reminder on the tree? Builder rolli has assembled these absolutely charming miniature scenes from throughout the series. There's a key in the description on Flickr, but I'd recommend puzzling them out first, they're SO good!