For the zombie Christmas idea, I'd suggest stringing him up with lights or hanging him from a rafter with a silky bow. If you wanna include Hanukkah, you could go with the menorah idea . . . or somehow have the zombie eat latke-people? ^^*

Believe it or not, the tree does have something to do with Christmas. It's a pagan symbol adapted to celebrate the birth of grace that came in the dead of winter, like an evergreen in the midst of bare branches. Candles, which later became electric lights for safety, also come from this concept. Bit of trivia. ^^