The Monocerus is a legendary animal from various cultures that have one horn only. It was derived from the Greek word Μονόκερος, a compound word from μόνος (monos) which means one and κέρας (keras) which means horn.
Although the name has been applied to a variety of genuine and mythological animals, it is usually applied to the unicorn or rhinoceros. Medieval bestiaries describe the monocerus as "having a stag's head, a horse's body, an elephant's feet, a boar's tail, and a single very long black horn growing from the forehead. It makes deep lowing sounds. The Monocerus is the enemy of the elephant and when fighting, it aims at the belly of its opponent". The Monocerus is probably based on the African Rhinos or the Indian Rhinoceros (Rhinoceros unicornis).