In Germany, they call compost "the Diet of Worms."
Also, s Caesarian section, in German, is called a "Kaiserschnitt."
My all-time favorite: there is no such thing as a live sardine!
The strangest folk tale, for my money, is the old French legend called "Bluebeard." This sex-and-violence-laden tale concerns a serial killer who also enjoys getting married, and because word of his homicidal tendencies has leaked out, all the local families avoid him.
But old Barbe Bleu convinces one of the local maidens to marry him after laying on a sumptuous banquet for two, of course. You'll have to go to Wikipedia for the ending -- I don't want to spoil it for anybody.
I've always, since I was a little kid, gotten scared by this story, but I don't know why.