Reptile or Amphibian? An Identification Key - ThoughtCo This key assumes that you are pretty certain the animal you're identifying is an amphibian or a reptile of some kind. For instance, this key doesn't apply to creatures that have feathers, fur, fins, or six legs and compound eyes—if you're observing any such animal, then you're not dealing with a reptile or an amphibian. Juvenile and Adult Amphibians of Alberta - ACA Amphibian Identification. To identify an amphibian, start with the images below. If you don't see what you're looking for, proceed to the Identification Key below the images and choose the best option that describes the juvenile or adult amphibian in question. Note that juvenile amphibians typically appear as scaled-down versions of the adults.