Centaur vs lusus naturae

Centaur

noun
  • One of a race of monsters having a head, torso, and arms of a man, and the body and legs of a horse. Often depicted as rowdy drunkards, with Chiron being a notable exception. 

  • A skillful horseman or horsewoman. 

  • A U.S. upper stage, with a restartable liquid-propellant engine, used with an Atlas or Titan booster to launch satellites and probes. 

  • An icy planetoid that orbits the Sun between Jupiter and Neptune 

lusus naturae

noun
  • An organism exhibiting marked such deviation from the norm, seeming to be the result of sportive design; a freak of nature. 

  • A sportive quality in Nature to which abnormal forms were formerly ascribed; a supposed capricious act of Nature regarded as the cause and origin of anomalies in a given organism. 

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