Created by the magical residue of thousands of unfortunate archmages who met their doom on the astral plane, the astral glutton is a fearsome thing. A worm-like ghost, it passes through the material world, becoming solid just long enough to tear apart the flesh of creatures it has been angered by. It’s favourite activity is to possess the living and live through them — not “vicariously,” exactly, since the astral glutton experiences every pleasure directly and the host body suffers all the consequences — in order to sate its alien appetites.
It would not have access to this world, of course, were it not for the lure of magical power. Those fallen sorcerers, floating in limbo between the stars, still retain vast quantities of the quintessence that is the arcane itself. What would you pay for such a treasure? It is like gold to the poor, weapons to the oppressed, or water to a man dying in the desert. Mages of all stripes lust after this pure arcane power, but to get it, they must venture between dimensions, and risk encountering something things best left beyond the veil — things like the astral glutton.