The 2017 holiday PixelCard is now available: Holiday Memories 2017.
Here are the cards that appear in the game.
Candy Cane


First appearance: 2009
Fireplace


First appearance: 2010 (although it was updated for 2017)
Gift


First appearance: 2010
Owl


First appearance: 2013
Penguin


First appearance: 2009
Polar Bear


First appearance: 2009
Snowman


First appearance: 2009
Window


First appearance: windows and snow have feature as smaller components of various cards. This one was created in 2017.