What are amphibious?

Famous quotes containing the word amphibious:

    “swirling crustacean-
    tailed equine amphibious creatures
    that garnish the axle-tree! What
    a fine thing! What unannoying
    romance!”
    —Marianne Moore (1887–1972)

    “We are amphibious creatures, weaponed for two elements, having two sets of faculties, the particular and the catholic.”
    —Ralph Waldo Emerson (1803–1882)