A room-filling province boss the festering ghouls form by fusing together at station 48 — a screaming mass of mouths.
The ghoul amalgamation is the answer to the floor's central dread: what happens when enough Festering Ghouls gather. Their goal is to converge on the stairwell room at station 48, where — Imani and Elle McGib witness — worm-things erupt from them and pull the ghouls tightly together into a single giant frankenmonster that completely fills the room, too big to leave it. A province boss whose mere discovery grants achievements, it slurps as it moves and is covered in ceaselessly screaming mouths, reminding Carl of the shambling berserkers of the prior floor, but larger.
It reveals the floor to be not a maze but an "almost-perpetual engine" building these horrors at multiple stations.
A colossal, room-filling fused mass of ghoul bodies bound by worm-things, its surface covered in endlessly screaming mouths, slurping wetly as it shifts.
A province-boss horror the festering ghouls assemble into at station 48 — the culmination of the floor's ghoul engine.