The rhinoceros, commonly known as rhino, is a large mammal found in Africa and Asia. Rhinos are herbivores and have a thick protective skin that is often covered with a layer of mud to protect themselves from the sun and insects. Rhinos are famous for their horn, which is made of keratin and is used by them for defense, digging, and marking territory. However, the horn is also highly valued in some cultures for medicinal and ornamental purposes, leading to poaching and a drastic decline in rhino populations.