Reptiles are a class of animal that inhabit the earth. Their name comes from Latin, and it means "one who creeps". They are one of the largest classes of vertebrates in the world. They all lay eggs and breathe through lungs, in addition to that they have scales. All reptiles are cold-blooded, which means that they cannot heat themselves up.
One of the best known types of reptiles are snakes. All snakes have plated skin, which can be compared to an armor of sorts. For example, this Spiny Bush Viper looks a lot like Smaug from Lord of the Rings.
Some reptiles have venom in fangs that they use to kill their prey. One bite of a Spiny Bush Viper can sometimes kill you, but most likely will make you vomit. Some snakes such as the Black Mambas paralyze and kill you with one bite.
Snakes do not have nostrils, they can smell using their tongues. This is the reason why snakes always are seen flitting their tongues out at the ground.