Living Black Hole
The Living Black Hole was an entity documented in Jenny Everywhere: Secret Origins, a comic book about the origins of Jenny Everywhere which the real Jenny stated was partially inaccurate.
The Living Black Hole was described as an intelligent force of destruction from outside the universe. After entering the universe in question it set about consuming it, system by system, causing the stars to go out one by one in the skies of Earth. It ultimately destroyed Earth as well, with the exception of a baby Jenny Everywhere, who survived thanks to having been placed in the Pod by her parents. (COMIC: The Secret Origin of Jenny Everywhere)
Behind the scenes
It is possible (though this was likely not the intent of the various creators involved) that the Living Black Hole is the same being as the Destroyer from PROSE: Where Is Everywhere, and/or as the Entity from COMIC: Makeshift Multiverse.
