Diceros simus, also known as the black rhinoceros or hook-lipped rhinoceros, is a critically endangered large mammal native to Africa. Synonyms for Diceros simus include the African black rhino, the eastern black rhinoceros, and the Cape rhinoceros. Despite being called "black," the rhino is actually gray in color. Diceros simus mainly feeds on foliage and fruits of trees and shrubs and has no natural predators due to its size and tough skin. However, poaching and habitat loss have caused a significant decline in their population, making them one of the world's most endangered species. Conservation efforts are currently underway to protect and restore their populations.