Fish have fins. Characteristics of Amphibians Amphibians have backbones. Amphibians are cold-blooded. Amphibians first breathe with gills, and then they breathe with lungs. They go through metamorphosis.
Amphibians lay eggs.
Amphibians have smooth, moist skin. Characteristics of Reptiles Reptiles have backbones. Reptiles are cold-blooded. Reptiles breathe with lungs. Reptiles lay eggs.