mocker vs thrasher

mocker

noun
  • A person who mocks. 

  • A mockingbird. 

thrasher

noun
  • One who thrashes. 

  • Any of several New World passerine songbirds, of the genera Toxostoma, Allenia, Margarops, Oreoscoptes and Ramphocinclus in the family Mimidae, that have a long, downward-curved beak. 

  • A fan of thrash metal music. 

  • A thresher shark. 

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