It is indeed a thing, and no, it's not slang. It is in fact the most expensive coffee in the world, as each coffee bean/berry has to have been eaten by a civet of some kind, then well, expelled, and then picked out of each bit of poop and presumably washed and processed. It's supposed to enhance the taste. I will let someone else here try it and report back if that is indeed the case.
Also, I do not want the job of picking the bean out of the poop. Just to be clear.