myrmidon vs underling

myrmidon

noun
  • A soldier or a subordinate civil officer who executes orders of a superior without protest or pity (sometimes applied to bailiffs, constables, etc). 

underling

noun
  • A subordinate, or person of lesser rank or authority. 

  • A low, wretched person. 

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