Animal Planet: Frogs and amphibians guideAmphibians include frogs, toads, newts, salamanders, and caecilians. They are cold-blooded vertebrates, and usually scaleless. Amphibians are animals which spend part of their life in aquatic (water) and a different part of their life cycle in terrestrial (land) environments. They usually start out their lives in water, and then move onto land as they mature, though, as adults, they may breed and spend a large amount of time in the water.