A rhinoceros (/raɪˈnɒsərəs/, from Greek rhinokerōs, meaning 'nose-horned', from rhis, meaning 'nose', and keras, meaning 'horn'), commonly abbreviated to rhino, is one of any five extant species of odd-toed ungulates in the family Rhinocerotidae, as well as any of the numerous extinct species. Two of the extant species are native to Africa and three to Southern Asia. The term "rhinoceros" is often more broadly applied to now extinct relatives of the superfamily Rhinocerotoidea.
Rhinoceros are killed by some humans for their horns, which are bought and sold on the black market, and used by some cultures for ornaments or traditional medicine.
The horns are made of keratin, the same type of protein that makes up hair and fingernails. Both African species and the Sumatran rhinoceros have two horns, while the Indian and Javan rhinoceros have a single horn. For more info check out Wiki Rhinoceros