Royalty in the unicornfox specie is caused by some kind of mutation. The horn is smooth, and usualy longer.
They often make themselve brightly coloured, and wear necklaces, bracelets, jewels, etc... to make themselve more visible. Unicornfoxes are often seen as vain. They also tend to paint their horn and hooves with gold or silver.
Royalty isn't based on family, but on the rare mutation that makes their magical powers greater than the common unicornfox. Since they live for a really long time (the norm is around 5000 years), mostly princes and princesses make the royalty, and they become kings and queens as soon as they chose a mate. It is then possible for the same kingdom to have more than one king/queen.
Even though it happens, it is badly seen for a prince or princess to chose a mate in the common unicornfoxes.

more infos on the specie

adopted by  Kalylia