Cats and Christmas trees don't always mix well. I have a vivid recollection of the year in my childhood when our black cat decided the six foot high, tinsel-draped addition to the living room was something to be climbed. Forever after my parents wired trees to nearby window frames. The cat was not ousted; rather the tree was restrained.
Via Ronni Bennett here's Oskar the Blind Kitten discovering the joys of Christmas. Apparently Oskar is a bit of a web phenomenon. There are many clips of his antics.