But that isn't right. The King of Beasts shouldn't be a coward,'" said the Scarecrow. 'I know it,' returned the Lion, wiping a tear from his eye with the tip of his tail. 'It is my great sorrow, and makes my life very unhappy. But whenever there is danger, my heart begins to beat fast.' 'Perhaps you have heart disease,' said the Tin Woodman. 'It may be,' said the Lion.
L. Frank Baum (2013). “Oz, the Complete Collection, Volume 1: The Wonderful Wizard of Oz; The Marvelous Land of Oz; Ozma of Oz”, p.36, Simon and Schuster