grampus vs hellbender

grampus

noun
  • The hellbender salamander, Cryptobranchus alleganiensis. 

  • Risso's dolphin, Grampus griseus, with a blunt nose. 

  • The killer whale, Orcinus orca. 

  • giant whip scorpion (Mastigoproctus giganteus) 

hellbender

noun
  • A giant salamander (genus Cryptobranchus) of North America that inhabits large, swiftly flowing streams with rocky bottoms. 

  • A reckless, headstrong person. 

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