Few things are worse than the hungry undead. But a ghoul will only feast on you. A devourer will sup on your soul—and then consume it like kindling to feed its magic. For GMs, devourers also inspire questions that in turn can inspire adventures: Who was this devourer originally? What transformed it, and where? And why has it returned?
The knightly Order of St. Manx seeks proof of the demise of the devil that killed the order’s founder. In fact, said devil may not have been slain—some say the fiend’s broken essence lives on in a particularly bloated devourer called the Gravid Maw, an apotheosis brought on by the devil’s multiverse-spanning flight from St. Manx’s vengeance. The Blade Proctor of the order will not rest until he receives word that the Gravid Maw, too, has been slain.
A certain codex in a certain library is known to devour souls. It is kept under lock and key, assumed to be a work so blasphemous mortal men cannot safely read it. In actuality, the codex is a devourer trapped in book form. If it is removed from the library, the curse will be lifted, and the devourer will thank its rescuers by attempting to slay and consume them immediately.
There is a sentence the Dread Court of Pontefract has handed down only four times in living memory: imprisonment of the soul. For the convicts, their prison and jailor are one and the same, a devourers bound by a special geas known as the Warden. Over time the geas has begun to weaken, and the Warden now merely bides its time until it can shatter its magical fetters completely. When the mage-bailiffs of the Dread Court try to compel it to release one of its charges, a paladin wrongly convicted of treason 20 years ago, they will find a very uncooperative—and hungry—undead monstrosity.
—Pathfinder Bestiary 82