Surprisingly, my search for zombified Christmas wreaths turned up more than almost any category - even tree ornaments. Many of them are DIY, so consider some of these as fun holiday craft projects.
DIY: Spider Wreath
For the less crafty among us...
Black and orange mesh wreath
Bloody body parts wreath
Cthulhu wreath! (is there anything Cthulhu can't do?)
Orange skull wreath