multiform vs polymorphous

multiform

adj
  • Having more than one shape or appearance. 

noun
  • An organism, folktale, etc. that appears in more than one form. 

polymorphous

adj
  • Having, or assuming, a variety of forms, characters, or styles 

  • Having, or occurring in, several distinct forms 

  • Crystallizing in two or more different forms; polymorphic 

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