It seems that celebrating xmas in Barcelona is special. From Damien Simonis' "Barcelona"; the underline is made by me:

POO-POOING CHRISTMAS

A Catalan Christmas wouldn't be the same without the pessebres (nativity scenes). A giant one is set up in Plaà§a de Sant Jaume and you can see a display of them in an annex of the Església de Betlem. These cribs are common throughout the Catholic world, particularly in the Mediterranean. What makes them different here is the scatological presence ““ along with the baby Jesus, Mary, Joseph and the three kings ““ of the caganer (crapper), a chap who has dropped his pants and is doing number twos (a symbol of fertility for the coming year).

On a similar note, the caga tià³ (poop log) is a wooden beast that “˜lives' in the kitchen or dining room in the run-up to Christmas and has to be “˜fed' (traditionally things like dry bread and water) so that on Christmas Day it will cagar (shit) gifts. Once, the gifts were sweets. In some families they tend to be more substantial nowadays.