Void Dragons:

Intrestingly enough, the life cycle of a void dragon starts as any other. Hatched from an egg, deep in the ocean. Void dragons have no limits and will consume and grow indefinitely....Eventually turning to eat the core of their own planet... once their planet has been consumed, they take to space in search of moons and other sources of power.

It is unclear whether their source of power is heat energy, radiation, or some unknown cosmic force.

Their magic allows them to adapt to new environments as they grow in size. In the early stages of life, they are well adapted to deep seas. It takes thousands of years for them to grow to a size where they become truly threatening... and only one out of every million truly reach catastrophic size. Most are destroyed the second they are discovered.