I recently gave a presentation on kappas, mischievous water sprites of Japan, in my language school. I learned a couple interesting phrases on the way:
Now my favorite:
What can I say, when I speak Japanese, I am a kappa on dry land, and even kappas drown sometimes, though swimming should be a fart in the water for them.
Bonus: Jeff gave a good answer when I asked for a translation of １０年で 嫁は寝肥り オレ河童. Why did his translation include Jack Sprat? Check out his comment and see why!