Oh la vache!

French cows in Asserac.   You have to eat them before they eat you.

As it turns out, knowing the word "la vache," which literally means "the cow," is very useful in French slang.  For example, if you see something unexpected, but really awesome, you can say "oh la vache!"  to express amusement and astonishment.  Or, if something goes wrong, you can say "oh la vache!" but with a more somber or angry tone to express discontent or anger.  Similar to the expression "holy cow!"

The French, however, take their fascination of cows further.  Vache can also be used as a modifier, like in the phrase "C'est vachement bien!"  Adding an "-ment" to the end of a word in French is equivalent to adding an "-ly" to the end of a word in English.  So this sentence means "It is cowly good!" but translates to "It is VERY good."  Note, however, that "vachement" is only used amongst friends or other familiar people and should never be used in polite or formal conversations.

There are also a few sayings with vache.  For example, "il chant comme une vache espagnole," meaning "he sings like a spanish cow."  That is to say, he sings very poorly.  Or, if someone parked their car across three spots, one might say "se garer comme une vache," literally translating to "park [a car] like a cow."  You see, cows are both good and bad in France.  Also delicious.

Here is my favorite cow-related joke:
Knock knock!
Who's there?
Interrupting cow.
Interrupting c....
MOOOOOO!