Malivore

Malivore is an ancient entity created millennia ago by an alliance of Nightworlders to devour and imprison the dragons and other rampaging supernaturals. Since that time, Malivore has been reduced to a bottomless black pit in which lays an infinite dimensional abyss where the dragons and other creatures slumber. Malivore's destruction at the hands of Gabriel Mikaelson inadvertently allowed all of these creatures to escape, eventually leading to the exposure of the supernatural and dawning of the Next Age, in which both humans and nightworlders reign together.