dang, now i'm gonna have to learn finnish

don't know if it's in there or NOT, but my favorite is italian and it's

gatsu piedi

(you figure it out)

Glorious, elaborate, profane insults of the world
Cory Doctorow 

An open Reddit thread entitled "What are your favorite culturally untranslateable phrases?" rapidly degenerated into a collection of rollicking, profane, grotesque insults, each more alarming and delightful than the last. Read the whole thing, of course, but here are some of the less profane examples:..........

(Image: Okay, so it's funny., a Creative Commons Attribution (2.0) image from andrewbain's photostream)