cool cat vs thick-skinned

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. 

thick-skinned

adj
  • Having a thick skin. 

  • Insensitive to the feelings of others; callous. 

  • Not easily offended. 

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