least weasel vs viper

least weasel

noun
  • The common weasel, little weasel, or simply weasel (Mustela nivalis), the smallest member of the weasel genus Mustela, native to Eurasia, North America, and North Africa. 

viper

noun
  • A venomous snake in the family Viperidae. 

  • A dangerous, treacherous, or malignant person. 

  • A person who smokes marijuana. 

  • Any venomous snake. 

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