bugbear vs goblin

bugbear

noun
  • An ongoing problem; a recurring obstacle or adversity. 

  • A source of dread; resentment; or irritation. 

verb
  • To alarm with idle phantoms. 

goblin

noun
  • One of various hostile supernatural creatures, now especially (fantasy literature) a malevolent and grotesque diminutive humanoid, often associated with orcs or trolls. 

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