errand boy vs harbinger

errand boy

noun
  • Someone in a responsible position who performs relatively menial tasks for a senior manager. 

  • A male employed to run errands. 

harbinger

noun
  • A person or thing that foreshadows or foretells the coming of someone or something. 

verb
  • To announce or precede; to be a harbinger of. 

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