Which of the following is a characteristic of an amphibian?

The characteristic that defines amphibians is their ability to live both in water and on land. Amphibians, such as frogs, toads, and salamanders, undergo a unique life cycle that typically includes an aquatic larval stage, where they often have gills and live in water, and a terrestrial adult stage, where they usually have lungs for breathing air. This dual lifestyle allows amphibians to thrive in both environments, making them distinct from other animal groups.

The other options do not appropriately describe amphibians. Unlike mammals, amphibians do not have fur covering their bodies. While some animals do have wings and are capable of flight, amphibians do not possess this trait. The mention of being cold-blooded in the incorrect option does relate to amphibians, but the phrase "cold-blooded warm habitat" is not a correct characteristic, as amphibians are cold-blooded animals that often require moist environments, which can vary in temperature.