Are the two parent's phenotype(outward look) solid black?, or are they patterned just like the hatchling there?
The reason I ask this is because
some Mexican Black kingsnakes(L.g.nigrita) aka MBK's can hatch with pattern and coloration
EXACTLY like Desert kings(L.g.splendida) do, but later develop into solid black individuals as they mature. This generally takes several months or more for MBK's to totally darken up fully. Desert kings(splendida) on the other hand keep the same pattern throughout their adulthood.
Anyway, just thought I would ask since the title said "Black king" and not Desert king, or splendida. These two are very closely related anyway(if not the very same animal), and it has been theorized by more than a few authorities that the Black kings are simply a Mexican Sonoran Desert clinal variant form of
melanistic(excessive black pigment) L.g.splendida. This is also my opinion regarding them too. One day they could very well be classified taxonomically as the very same subspecies. But until then they are basically either type depending on their adult phenotype.
I have had both types, and they are definitely neat little hardy snakes, so have fun with it whatever the case happens to be.
cheers, ~Doug