"Beings known as aberrations are very rare by most accounts, thankfully so, as there is not many things that are as terrifying and incomprehensible. A lot of cultures see them as the antithesis of everything that is good and natural, the antithesis of all life. Their appearance is so infrequent however that several generations may pass before one appears. Few know how they are formed however. Aberrations are formed when someone talented with magic attempts to grasp too far into the nether in search of too potent magic. If the person is talented enough, they will open a portal into the nether through themselves, allowing the creatures within to use this person as a vessel to transport themselves into this world, essentially killing the person in the process or driving them insane. Indeed just witnessing one is enough to make one question everything they know."