big cat vs king of the beasts

big cat

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

  • Any large feline animal, especially one of the Panthera genus, including tigers, lions, jaguars and leopards. 

king of the beasts

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