jackass vs jacko

jackass

verb
  • To behave very obnoxiously. 

noun
  • A male donkey. 

  • A foolish or stupid person. 

  • An inappropriately rude or obnoxious person. 

  • A jack and an ace as a starting hand in Texas hold 'em. 

  • A kind of bootleg liquor. 

jacko

noun
  • laughing kookaburra 

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