chimpanzee vs fathead

chimpanzee

noun
  • A member of the genus Pan, including the bonobo which is also known as the pygmy chimpanzee. 

  • Pan troglodytes, a species of great ape in the genus Pan, native to Africa, and believed by biologists to be the closest extant relative to humans along with the bonobo. 

fathead

noun
  • Any of several species of fish of the genus Cubiceps 

  • An idiot; a fool. 

  • A blobfish, Psychrolutes microporos 

  • A labroid food fish of California; the California sheephead. Semicossyphus pulcher. 

  • A cyprinid fish of the Mississippi valley, Pimephales promelas, the black-headed minnow. 

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