Dictionary.com
Thesaurus.com

biped vs. quadruped

[bahy-ped] / ˈbaɪ pɛd /

noun

  1. a two-footed animal.

adjective

  1. having two feet.

[kwod-roo-ped] / ˈkwɒd rʊˌpɛd /

adjective

  1. four-footed.

noun

  1. an animal, especially a mammal, having four feet.