The Tió de Nadal (Catalan pronunciation: [tiˈo ðə nəˈðaɫ], Western Catalan: [tiˈo ðe naˈðaɫ]; meaning in English “Christmas Log”), also known simply as Tió(“Trunk” or “Log”, a big piece of cut wood) or Tronca (“Log”), is a character in Aragones and Catalan mythology relating to a Christmas tradition widespread in Aragon and Catalonia. A similar tradition exists in other places, such as the Cachafuòc or Soc de Nadal in Occitania. In Aragon it is also called Tizón de Nadal or Toza.
Often popularly called Caga tió (“Shitting log”, “Poo log”), the form of the Tió de Nadal found in many Aragones and Catalan homes during the holiday season is a hollow log about thirty centimetres long. Recently, the Tió has come to stand up on two or four stick legs with a broad smiling face painted on its higher end, enhanced by a little red sock hat (a miniature of the traditional barretina) and often a three-dimensional nose. Those accessories have been added only in recent times, altering the more traditional and rough natural appearance of a dead piece of wood.
Beginning with the Feast of the Immaculate Conception (December 8), one gives the tió a little bit to “eat” every night and usually covers him with a blanket so that he will not be cold. The story goes that in the days preceding Christmas, children must take good care of the log, keeping it warm and feeding it, so that it will poop presents on Christmas Day, hence the name caga tio (literally, “poo log”).