bad seed vs malignant

bad seed

noun
  • A genetic source of bad behavior or other negative results. 

malignant

noun
  • A deviant; a person who is hostile or destructive to society. 

adj
  • Harmful, malevolent, injurious. 

  • Tending to produce death; threatening a fatal issue. 

How often have the words bad seed and malignant occurred in a corpus of books? (source: Google Ngram Viewer )