"Unicorn" is a bit of a misnomer, as the singular horn is actually not a horn at all, but a tusk, or elongated tooth, similar to that of an elephant or a narwhal.

The unicorn is an anomaly because it is a grazing animal, but the giant tusk makes it very difficult to traditionally graze. The unicorn evolved around this by employing a prehensile trunk, which it uses to pick long grasses and leafy forage. Bull unicorns are larger than cows, and have longer tusks, which they use to spar.

Sparring or "jousting" with these deadly weapons can easily cause severe injuries or death. As such, unicorns developed an elaborate and intense display system of dancing and rearing to intimidate rivals, and will typically only fight as a last resort.