All reptiles are cold-blooded and their skin is covered with scales as opposed to feathers or fur. They range in size from tiny geckos measuring less than 2 cm in length to saltwater crocodiles that can reach 5.5 m in length and weigh more than 1 000 kg. Most reptile species lay eggs (oviparous); the embryo develops inside the egg and outside the mother's body, without a larval stage.