green dragon vs mad hatter

green dragon

noun
  • A tincture of cannabis, typically made by soaking the flowers, leaves, or stems in ethyl alcohol. 

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

  • Any of several plants in the family Araceae, including the North American species Arisaema dracontium and the Asian genus Pinellia. 

mad hatter

noun
  • A lunatic; a highly eccentric person. 

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