mustela vs viper

mustela

noun
  • Any of the carnivorous mammals of the genus Mustela. 

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 mustela and viper occurred in a corpus of books? (source: Google Ngram Viewer )