Ghosteater

The Ghosteater is a fairly benign creature, an incorporeal who feeds on other incorporeals. It's kind of obvious.

In the City of Manifest, they can be a bit of a problem.

In the Ghostwalk campaign there's a special city and surrounding area where life and death have a grey area in between, the City of Manifest and the Spirit Wood, which lie over the Veil of Souls (a weak point in the barrier between Life and Death). Due to interplanar shenanigans, loss of a body doesn't mean your soul has to cross over right away. In fact, anyone who dies in this area can choose to either move on or stay in the Material Plane as a ghost, though they will eventually find themselves drawn to the Other Side.

What I'm saying is that Manifest has a lot of ghosts living and working and generally being functional members of society. Having a Ghosteater running around is like having a tiger running around in a regular city of people made of tasty meat.

The Ghosteater is only ever aggressive to ghosts and ignores corporeal creatures. It has growths on its back, something like sacks or boils, that can exude tentacles to grab ghosts. This is very mentally draining for the ghost and when incapacitated, the ghost is aborbed into the growth, where it's digested. Maybe you can call this digestions a True Death, since when the soul is gone there's just no more existence.