nymph vs pixie

nymph

noun
  • Any of various butterflies of the family Nymphalidae. 

  • The larva of certain insects. 

  • Any female nature spirit associated with water, forests, grotto, wind, etc. 

  • A young girl, especially one who is attractive, beautiful or graceful. 

pixie

noun
  • A butterfly of the genus Melanis. 

  • A cute, petite woman with short hair. 

  • A playful sprite or elflike or fairy-like creature. 

  • An upper-atmospheric optical phenomenon associated with thunderstorms, a short-lasting pinpoint of light on the surface of convective domes that produces a gnome. 

How often have the words nymph and pixie occurred in a corpus of books? (source: Google Ngram Viewer )