What the heck is a Caganer?
A caganer is a figurine of a person or something doing his or her..ahem...business.
And why does this thing exist?
The caganer is a Catalonian Christmas tradition, dating back to at least the 1700s. Caganers are placed in nativity scenes, usually hidden at the side or back (not in the manger scene itself). It's a Christmas tradition for children to find the caganer. Caganers are often thought to symbolize good luck or fertility.
Ewww. That's gross.
Well, to each his (or her) own. We happen to find them delightful.