lap dog vs myrmidon

lap dog

noun
  • A person who behaves in a servile manner, such as a sycophantic employee or a fawning lover. 

  • A small toy dog, kept as household pet, whose light weight and companionable temperament make it both suited and disposed to spend time resting in the comfort of its master's lap; a dog bred to behave in this manner. 

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). 

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