Dave Thau, an old friend from the Wired days, sent me an email I thought was worth sharing:
I'm writing to report to you about a couple of Catalan Christmas artifacts you may not know about.
First I will describe the caganer – a wholesome and fun Catalan addition to the typical Christmas creche figurine family. The traditional caganer is an old Catalan man with a red hat and canvas shoes squatting and taking a dump in the manger. Over time, the theme has expanded to include sumo wrestlers, Santa, the Devil, the Pope, Dali, and soccer fans, just to name a few. There's a good site describing them, and selling about 60 different varieties: www.caganer.com. Here's a link to their shop.
In Barcelona there's a temporary market of stalls in the Placa Nova which sell the caganers and a host of other Christmas paraphernalia, including the next member of the Catalan Christmas family: caga tio. I've attached a picture of ours (click image for enlargement).
Caga tio comes in many sizes, but generally looks just like our new friend, sans the pipe. Customs surrounding caga tio differ, but all agree, caga tio means "shit log." Here I relay to you what I think is the full blown caga tio ritual.
Fifteen days before Christmas, caga tio makes his appearance in the dining room, where he must be fed at least once every day. He likes oranges, crackers and sweet wine. In some families, caga tio starts small, but grows as the days progress toward Christmas.
At some point, caga tio is moved out of the dining room, into the living room, and covered with a blanket to keep him warm. On Christmas Eve, before the traditional Christmas dinner, the kids are sent to their rooms to say three Our Fathers, which gives the elders enough time to stash presents under caga tio's blanket. After their prayers are done, the kids return to the living room and start beating the hell out of poor caga tio with big sticks. And they sing a song. One version goes "Shit, log, shit! If you don't shit well, we will whack you again!" Another goes "Log, log, shit candy! If you don't shit for Christmas, we will whack you once more!"
After the children have gotten their fill of flogging the log, the blanket is removed to determine caga tio's state of digestion. Typically, a miracle has occurred, and the log has pooped wrapped gifts, which are called "the shits." Often one of the shits will be something weird, like an egg, to let everyone know that it was the last one deposited by caga tio.
This is my understanding of caga tio, but I feel like there are probably many nuances I'm missing. If you know of any catalans, please let me know so I can ask them some questions.
Ah, another exemplar of Catalan Christmas coprophilia is candy shaped like poo. We got some of this stuff, but ate it all before we could take a picture of it. If you're interested, we'll hunt more down tomorrow. Acutally… it was GOOD – we're getting more tomorrow no matter what!
We're documenting all this, and other Barcelona extravagances in our blog.
UPDATE: 
Here are some more caga tio pictures from Dave Thau (click image for enlargement)
