Yak Fic
From Super-wiki
I didn't see anything here, so I thought I'd make an entry.
Definition
Yak Fic means any story in which the characters either are attracted to Yaks (possibly because of a spell), talk about Yak fucking, or dress up in a yak costume (I read about it in a fic! I swear!). Or if Dean says Sammy has Yak-hair. Which he kinda does sometimes.
See the Crack page for a list of Yak Fucking fics.