Yes, listen to me, it’s the lake speaking. If you want to avoid being eaten by the Serpent King of this island, take off your clothes and spread them on the path that leads from here to the castle.

It pleases the king to glide over something  soft, and, by the time he reaches you, he will be so pleased that he will not likely devour you.

The Lake in The Seven-Headed Serpent, Yellow Fairy Book