biped vs two-footed

biped

noun
  • An animal, being or construction that goes about on two feet (or two legs). 

two-footed

adj
  • Using both feet. 

  • Having two legs or feet. 

  • Ambidextrous of the feet; having equal ability with either foot. 

How often have the words biped and two-footed occurred in a corpus of books? (source: Google Ngram Viewer )