dog's tongue vs tentacle

dog's tongue

noun
  • The plant hound's tongue. 

tentacle

noun
  • One of the glandular hairs on the leaves of certain insectivorous plants. 

  • An officer employed to drive out to troops and transmit back requests for support via a special radio link. 

  • An elongated, boneless, flexible organ or limb of some animals, such as the octopus and squid. 

  • An insidious reach or influence. 

verb
  • to move like a tentacle 

How often have the words dog's tongue and tentacle occurred in a corpus of books? (source: Google Ngram Viewer )