bite off vs pull teeth

bite off

verb
  • To accept or commit oneself to a task, project, notion, or responsibility, especially one which presents challenges. 

  • To bite so hard as to remove something from its source. 

  • To acquire, especially in an abrupt or forceful manner. 

pull teeth

verb
  • To do something that is especially difficult or effortful. 

  • To remove teeth, usually because they are diseased or damaged. 

How often have the words bite off and pull teeth occurred in a corpus of books? (source: Google Ngram Viewer )