El Caganer is a figure in Catalan nativity scenes, where he is often hiding in a corner doing his business whilst the birth of Christ, the most momentous event in Western history, is taking place.
A polite translation of El Caganer would be The Defecator and he is normally dressed in the traditional Catalan peasant clothing of a white shirt, black trousers and a red faixa and barretina and is often smoking a pipe.
In recent years, however, you can find many other caganer figures, including politicians, TV stars and footballers and bizarrely having a caganer in your image can be both an honour and an insult depending on how you are seen by Catalan society.
For example, having a caganer of an FC Barcelona player, such as Messi, is most likely an honour whereas if it's Cristiano Ronaldo or any other a Real Madrid player, it's definitely intended as an insult.
When it comes to politicians, things get a bit more complicated. Spanish ones are almost certainly being put down whilst how you interpret a caganer of a Catalan politician depends on recent events and the person in question's current level of popularity.
It appears that the origins of El Caganer date back to the late 17th century during the Baroque period, which was characterised by exaggerated realism.
Originally, El Caganer wasn't a figure in the nativity scene but was mainly depicted on tiles telling stories and only became popular as a nativity character from the 19th century onward.
How this happened is a matter of dispute but it has been suggested that Catalans traditionally referred to new-born babies as caganers because they do little else other than eat, sleep and defecate.
Consequently, when visitors came round at Christmas, they would look at the nativity scene and ask their hosts "Have you put in the caganer yet?" referring to the baby Jesus.
At some point an imaginative manufacturer of nativity figure must have decided to turn the tile character into a nativity model and so the tradition of El Caganer was born.
Another explanation is that El Caganer fertilises the ground with his faeces and so is considered a symbol of prosperity and good luck for the coming year so, although it might surprise prudish Anglo-Saxon Protestants, he is well accepted by both the Catholic Church and polite society here in Catalonia.
I still remember the mixture of shock and delight I felt when I stopped to look closely at the nativity scene in Barcelona's Plaça de Sant Jaume just before my first Christmas here back in 1988.
There were Mary, Joseph and the Baby Jesus, the Shepherds, Kings and Farm Animals all tastefully laid out with typical Catalan artistic panache and there in the background was a Catalan peasant doing the necessary while the most important event in Western culture is taking place.
Interestingly, El Caganer isn't the only defecating Christmas character in the Catalan Countries because we also have the Caga Tió, a pooping log who poops out presents when children hit him with a stick.
I don't know what it is about Catalans but their vaguely scatological obsession definitely strikes a chord with my mischievous northern English sense of humour.