crawbob vs crawchie

crawbob

noun

  • An Australian species of freshwater crayfish, Cherax destructor; a yabby. 

crawchie

noun

  • An Australian species of freshwater crayfish, Cherax destructor; a yabby. 

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