moorhen vs sabre-toothed tiger

moorhen

noun
  • A female red grouse, Lagopus lagopus scotica. 

  • Any of various medium-sized water birds of the genus Gallinula, of the rail family, that feed in open water margins. 

sabre-toothed tiger

noun
  • Any of numerous species of extinct cat-like mammals, of the Machairodontinae subfamily of the Felidae. 

How often have the words moorhen and sabre-toothed tiger occurred in a corpus of books? (source: Google Ngram Viewer )