bad boy vs tough cookie

bad boy

noun
  • An undesirable or difficult task. 

  • A male criminal. 

  • A powerful or impressive product or item. 

  • Used other than figuratively or idiomatically: see bad, boy. 

  • A man whose rebellious nature makes him dangerous and/or attractive. 

tough cookie

noun
  • Something troublesome or difficult to handle. 

  • A hardy, resilient animal or plant. 

  • A person who can endure physical or mental hardship; a hardened, strong-willed person. 

How often have the words bad boy and tough cookie occurred in a corpus of books? (source: Google Ngram Viewer )