It is a universal force, a consumer of souls. It is a being of the void, at times corporeal, other times ethereal: a monster between the planes. Even the Great Equalizer, Death, fears Der Großpony; the Tall Pony.
It is an ancient being of strange gravity, the abyss personified; a twisted voice from out the original darkness, before the first light appeared in the universe. It is the first collapsed star, a black hole grown complicated and sentient; It's motivations unknowable, It's power inexorable; a force of destruction unleashed upon existence itself.
And nopony, not even one from the Before Times, will be able to stop It.