lackey vs running dog

lackey

noun
  • A fawning, servile follower. 

  • A footman, a liveried male servant. 

verb
  • To attend, wait upon, serve obsequiously. 

running dog

noun
  • A lackey; a lapdog; an unprincipled person who helps or flatters other, more powerful and often evil people. 

How often have the words lackey and running dog occurred in a corpus of books? (source: Google Ngram Viewer )