S: (n) amphibian (cold-blooded vertebrate typically living on land but breeding in water; aquatic larvae undergo metamorphosis into adult form)
S: (n) vertebrate, craniate (animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium)
S: (n) chordate (any animal of the phylum Chordata having a notochord or spinal column)