Pantherism

All feline races are susceptible to a condition called "Pantherism" where their fur is completely black at birth. Though in rare cases late set Pantherism has been seen.
Though this genetic condition is most common in the Felis race it isn't unheard of in the Leonin and the Tabaxi races. When one is born with Pantherism in the Felis race especially, it's often seen as an omen and can be interpruted in a variety of ways. Either a sign of inate magic or for a bringer of death. Many new borns with this condition are taken or sent away to be raised and trained in the arcane arts or as an assassin as it is believed these are natural skills of the "Panther."
The connection to innate magic and Pantherism is made as in the rare case a Felis has seen Pantherism appear later in life is due to their magical practices. In these instences as the Felis in question powers grew so did their fur darken until it was purely black. Even though this is not always the case, as there are plenty of examples of Felis practicing magic and not having Pantherism appear.

Type

Genetic