The rhinoceros, often called rhino, is a large, thick-skinned herbivore native to Africa and South Asia. There are five species of rhinos: the white rhino, black rhino, Indian rhino, Javan rhino, and Sumatran rhino. They are known for their distinctive horns, which are made of keratin, the same material as human hair and nails. Rhinos typically inhabit grasslands, savannas, and tropical forests. They play a crucial role in their ecosystems by helping to maintain the balance of vegetation. Unfortunately, rhinos are threatened by poaching and habitat loss, leading to significant declines in their populations and conservation efforts to protect them.