Frogs don't just wear their skin, they drink and breathe through it, too! Many frogs even have a special drink patch on the underside of the body. Like a giant lung, the thin, moist skin allows gases to pass through, helping the frog to breathe. To keep the skin working well, frogs must stay clean and moist. They produce sticky mucus to prevent drying. Most frogs shed the outer layer of skin by twisting and stretching—they often eat the dead skin as it comes off.
Some of the bumps and "warts" that give frog skin its texture are clusters of specialized glands. Mucous glands lubricate the skin. Granular glands produce poisons and other protective chemicals.
The color of frog skin is the result of layers of pigmented cells. Most frogs can change the brightness of their skin by moving dark pigment up and down the tentacles of special cells called melanophores.