The Unholy Incarnation of Gluttony (Tony, for short) has been more or less benignly wandering the Network for nearly four hundred years, carefully controlled by its host and master, the kindly Eric Thedrial.
What IS Tony, exactly? Despite rumors and poetic phrasing, Tony is NOT a demonic entity representing a deadly sin, it is not actually even a separate being from Eric. Psychologically, Tony's what you get when you inhibit everything in the human mind save the powerful animal impulse to eat stuff. Religion/demons/sins really have nothing to do with Tony.
Tony is the result of a morality curse, meant to demonstrate to the once spoiled Lord Thedrial the essence of his greed by removing entirely his human willpower and control over base instincts (which he was so poorly exercising anyway) transforming him for periods into a destructive, self-destructive, mindless and mortifying mass of monster. And then returning him to human form to think about what he'd done.
Tony is largely a metapho