pickerel vs snake pickerel

pickerel

noun
  • A freshwater fish of the genus Esox. 

  • Walleye, A species of gamefish, Sander vitreus, native to the Northern U.S. and Canada with pale, reflective eyes. 

  • A wading bird, the dunlin. 

snake pickerel

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