lindworm vs rotter

lindworm

noun
  • A draconic creature, similar to a wyvern. 

  • A wingless serpentine dragon having two arms. 

rotter

noun
  • A scoundrel. 

  • A despicable, worthless person. 

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