A black dragon egg is an egg that can be collected as a drop from adult black dragons.
99 Summoning is not required to receive the black dragon egg as a drop.
You can incubate the egg to hatch a black dragon, but please note that a grown dragon pet will still only be a baby black dragon.
It takes 60 minutes in-game to hatch a black dragon egg.
You can have more than one egg of each color, but they will not be able to incubate and grow additional pet dragons unless their current pet dragon is fully grown and stored in the menagerie of their player-owned house.
What do Black Dragons Eat in Runescape 3?
Black dragons eat meat and fish. You must be at least 92 Farming to be able check and raise a Black Dragon.