firedrake vs flying dragon

firedrake

noun
  • A fire-breathing dragon. 

  • A fiery meteor, an ignis fatuus, a rocket 

  • A kind of firework 

  • A worker at a furnace or fire 

flying dragon

noun
  • Used other than figuratively or idiomatically: see flying, dragon. 

  • Draco volans, a gliding lizard endemic to Southeast Asia. 

  • Any lizard in the genus Draco. 

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