I finally decided to change the winter holiday theme on Firefox and was pleasantly surprised to find a Spelling Disaster staring right at me! We can add Chistmas to previous SDs of that December holiday: Chrsitmas Club and Chrsitmas Elf Yourself.
And don't be getting on my case about waiting until February to change the Christmas browser theme! That's not nearly as bad as waiting until February to take down the tree!!