cool cat vs in cold blood

cool cat

noun
  • An individual who is at ease and self-assured; one who is calm and composed in interactions with others. 

  • A person who performs or appreciates jazz, especially one whose style of speech and movement is relaxed and rhythmic. 

in cold blood

prep
  • In a ruthless and unfeeling manner, particularly as applied to first-degree murder committed without provocation and with malice aforethought. 

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