mollusc vs weakling

mollusc

noun
  • A weak-willed person. 

  • A soft-bodied invertebrate of the phylum Mollusca, typically with a hard shell of one or more pieces. 

weakling

noun
  • A person of weak character, lacking in courage and/or moral strength. 

  • A person of weak or even sickly physical constitution 

adj
  • weak, either physically, morally or mentally 

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