The monocerus is a legendary animal with only one horn. It derives from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word Μονόκερος, a compound word from μόνος (monos) which means one and κέρας (neuter gender

Grammatical gender

Grammatical gender is defined linguistically as a system of classes of nouns which trigger specific types of inflections in associated words, such as adjectives, verbs and others. For a system of noun classes to be a gender system, every noun must belong to one of the classes and there should be...

, keras) which means horn

Horn (anatomy)

A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...

. 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

Bestiary

A bestiary, or Bestiarum vocabulum is a compendium of beasts. Bestiaries were made popular in the Middle Ages in illustrated volumes that described various animals, birds and even rocks. The natural history and illustration of each beast was usually accompanied by a moral lesson...

 describe the monocerus as "having a stag

STAG

STAG: A Test of Love is a reality TV show hosted by Tommy Habeeb. Each episode profiles an engaged couple a week or two before their wedding. The cameras then follow the groom on his bachelor party...

's head, a horse's body, an elephant's feet, a boar

Boar

Wild boar, also wild pig, is a species of the pig genus Sus, part of the biological family Suidae. The species includes many subspecies. It is the wild ancestor of the domestic pig, an animal with which it freely hybridises...

's tail, and a single very long black horn

Horn (anatomy)

A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...

 growing from the forehead. It makes deep lowing sounds. It 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 or Indian Rhinoceros

Indian Rhinoceros

The Indian Rhinoceros is also called Greater One-horned Rhinoceros and Asian One-horned Rhinoceros and belongs to the Rhinocerotidae family...

(Rhinoceros unicornis)".