In Teutonic folklore, undines are female water-spirits who like to associate with humans. They often join villagers in their dances and merry-making. An undine was created without a soul, but by marrying a mortal and bearing him a child she obtained a soul and with it all the pains and penalties of the human race.

She is the subject of the tale Undine (1811) by Friedrich de la Motte Fouqué. The word was invented by the medieval scholar Paracelsus.