爬行綱, or Reptilia, is a class of animals that includes snakes, lizards, turtles, and crocodiles. These creatures are characterized by their scaly skin, which helps prevent water loss, and they are primarily ectothermic, meaning they rely on external sources to regulate their body temperature. Most reptiles lay eggs, although some give birth to live young. They inhabit a variety of environments, from deserts to forests, and play essential roles in their ecosystems as both predators and prey. Their adaptations allow them to thrive in diverse habitats around the world.