There are different classes of pessebre. In Catalonia it is usually build with vegetal objects like moss, cork and mud figures. The scene is always the same, Jesus birth in a cowshed near the virgin Maria, Sant Josep, a mule and a cow. Jesus is over the place where the animals eat, "el pessebre" in Catalan. The Cristian tradition reserved this modest place to the rescuer of the world.
In the "pessebre" we found other standardized characters, the poor, the wise and the indifferent. The poor are the shepherds that always adore Jesus and give him some presents. The wise are the three magician kings who came from the far orient guided by a comet. The indiferent people are some characters that work in their usual activities without notice about the Jesus birth. A curious tradition in Catalonia is to represent a man defecating in a reserved place. This character is "el caganer" and is a perfect representative of the scatological catalan cultural tradition. Now you can see all famous people represented as mud figures in action to defecate, as for example the catalan president Carles Puigdemon or the US president Donall Trump.