creature vs mammal

creature

noun
  • A living being; an animal. 

  • A being subservient to or dependent upon another. 

  • A human. 

  • A created thing, whether animate or inanimate; a creation. 

  • An unidentified, mysterious, and often monstrous animal or being. 

mammal

noun
  • An animal of the class Mammalia, characterized by being warm-blooded, having hair and producing milk with which to feed its young. 

  • A vertebrate with three bones in the inner ear and one in the jaw. 

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