As a Mythenmetz-fan, I had to get this one.
It is basically the luxurious "reprint" of a letter from Mythenmetz to Hachmed Ben Kibitzer, explaining (and criticising) the tradition of Hamoulimepp, which - like Hogswatch - resembles a mixture of our Christmas and New Year's Eve celebrations. I could very much sympathise with my favourite Lindwurm's position on these end of year celebrations and traditions.
If you are looking for a Christmas gift for a fan of Walter Moers and/or Zamonien, this might be it: It not only has a book jacket and ribbon, but is fully coloured and contains a surprising amount of artwork (although it isn't Moers' own hand doing the drawings here, but Lydia Rode whose style is less edgy and raw).