In this case, we're not looking for an X. Our hostess gave us a three items to find on book covers - a tree, snow and a weapon. This proved to be pretty easy on our bookshelves. I am nuts for anything Christmas, and especially for A Charlie Brown Christmas. The covers of any of my various copies contained both snow and a tree. But to keep things fair, I only counted it as "tree", and added Phillip Gulley's Christmas in Harmony as my "snow" entry. For weapons, I simply grabbed a paperback off of Dave's shelves containing the complete set of Louis L'Amour westerns. Nearly every book has a gun of some sort on the cover.
I found the treasure! and the prize is - - more hours of reading.