imp vs pixie

imp

noun
  • A small, mischievous sprite or a malevolent supernatural creature, somewhat comparable to a demon but smaller and less powerful, formerly regarded as the child of the devil or a demon (see sense 3.2). 

  • A mischievous child. 

  • A baby Tasmanian devil. 

verb
  • To add to or unite a object with (something) to lengthen the latter out or repair it; to eke out, enlarge, strengthen. 

  • To provide (someone or something) with wings, hence enabling them or it to soar. 

  • To engraft (a feather) on to a broken feather in a bird's wing or tail to repair it; to engraft (feathers) on to a bird, or a bird's wing or tail. 

pixie

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

  • A butterfly of the genus Melanis. 

  • A cute, petite woman with short hair. 

  • 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 imp and pixie occurred in a corpus of books? (source: Google Ngram Viewer )