This one does what it says on the tin. It's A Christmas Carol with zombies. The workhouse is being overrun as the starving poor begin to feast on the living. Oblivious to this, Ebeneezer Scrooge is visited by the ghost of his former business partner, Jacob Marley, who warns that through the night he will be visited by three more spirits.
The undead Jacob Marley.
Despite the zombies, Zombie Christmas Carol is actually closer to Dickens' original story than some other adaptations of it I've seen, at least in the first issue (though that starts to change as it goes on). The art is excellent, and it's a fun twist on the old tale.
2. Marley's Ghost by Harvey Kurtzmann
If you're looking for a more traditional version of A Christmas Carol, sans zombies, then there is Marley's Ghost. Kurtzmann, the creator of MAD Magazine, began his graphic novel adaptation of Dickens' tale in the '50s, but never completed it. More than 60 years later it has been brought to life by writers Josh O'Neill and Shannon Wheeler, who expanded on Kurtzmann's notes, and illustrator Gideon Kendall, who worked with and extended Kurtzmann's character concepts. It has been released in digital format by Comixology. It's a great version, that would be suitable for younger readers (aged about 8 and up).
The eponymous ghost.
3. The Wicked + the Divine Christmas Annual #1
The Wicked + The Divine is a contemporary fantasy series, in which the gods of various human cultures are reborn every 90 years into human bodies. Once they merge with a human host they live for only two years, so they make the most of it, partying hard or striving to inspire humanity. In this Christmas annual, which isn't really Christmas themed, though it does take place at the most wonderful time of the year), the writer Kieron Gillen, shows us some of the Pantheon's earlier fun times, before the beginning of the first plot arc of the series. There's a lot of fan service, with different characters getting together (quite graphically), and some truly atrocious puns from Baphomet.