Black Adder
Melanistic (black) adders are not uncommon in the wild and they may even be more successful than the normal colour form as their darkened skin cells means that they can have a thermoregulatory advantage, and can warm up quicker. Black individuals can therefore feed on days which would be too cold for other individuals. These advantages can be offset by an increased risk of being discovered and eaten by predators compared to the normal-coloured specimens which are better camouflaged.