anaconda vs boa constrictor

anaconda

noun
  • Any of various large nonvenomous snakes of the genus Eunectes, found mainly in northern South America. 

  • A large penis. 

  • The green anaconda; Eunectes murinus. 

name
  • A particular variety of stud poker. 

boa constrictor

noun
  • A large tropical American snake, Boa constrictor, that kills its prey by squeezing them. 

  • Any large python. 

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