The karkadann (Arabic: كركدن) is a unicorn known to the Muslims. It is described as the fiercest and most terrible beast alive. It inherits solitary and territorial character from the monoceros and carries it to such lengths that it will not suffer another animal grazing within a hundred parasangs from itself. It is a mortal enemy with an elephant; when it sees one, it jumps to a nearby tree and sharpens its horn on the trunk. Then it charges and thrusts its horn through the elephant's soft underside. However, it finds itself unable to remove the carcass from its horn. The elephant's fat melting in the sun gets into the eyes of the karkadann, blinding it so that it lies down on the shore. In the end, there comes the giant bird rukh and carries both the karkadann and the elephant off to feed its young.
The only animal karkadann tolerates is the ring dove.
The name has many variants. The most common are كركدنّ (karkadann) or كركدّن (karkaddan). Others include: كردنّ (kardunn), كركند (karkand or karakand), fem. كركندة (karkanda), كركدآن (karkadān) and كزكزان (kazkazān). Persian literature often uses كركدن (karkadan), کرگدن (kargadan) and کرگ (karg). They come most likely from Sanskrit खड्ग (khaḍga), which means "sword" or "rhinoceros", and खड्गधेनु (khaḍgadhenu), which is a name for a female of the species.
In the past "karkadann" was a generic name for a unicorn, so all other kinds have been described with that name, leading to much confusion. In modern Arabic, the word denotes a rhinoceros.