bag of dicks vs shithead

bag of dicks

noun
  • A rude, obnoxious, or contemptible person. 

shithead

noun
  • A stupid or contemptible person. 

  • A card game, the aim of which is to lose one's cards. 

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