fat cat vs milliardaire

fat cat

noun
  • A rich person who contributes to a political campaign. 

  • Any affluent person who is perceived to have profited from the labour of others. 

  • Used other than figuratively or idiomatically: see fat, cat. 

milliardaire

noun
  • A billionaire; somebody whose wealth is greater than one milliard (10⁹) dollars, or other currency. 

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