battler vs tough cookie

battler

noun
  • One who works hard in the face of adversity. 

  • One who wages battle against an enemy; a soldier; a general. 

tough cookie

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

  • A hardy, resilient animal or plant. 

  • Something troublesome or difficult to handle. 

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