dog's tongue vs mischief

dog's tongue

noun
  • The plant hound's tongue. 

mischief

noun
  • A group or a pack of rats. 

  • Casual and/or flirtatious sexual acts. 

  • A playfully annoying action. 

  • A criminal offence defined in various ways in various jurisdictions, sometimes including causing damage to another's property. 

  • Conduct that playfully causes petty annoyance. 

  • The Devil; used as an expletive. 

How often have the words dog's tongue and mischief occurred in a corpus of books? (source: Google Ngram Viewer )