"Carrion Crown" is a campaign arc of the Pathfinder role-playing game. It consists of six adventure modules: "The Haunting of Harrowstone," "The Midnight Mauler," "The Watcher of the Dead," "The Whisper Woods," "The Pallid Plague," and "The Asylum Stone."

In the campaign, the players must investigate a series of strange and terrifying events in the region of Ustalav, where the spirits of the dead are said to walk the land. The players must journey to various locations, including the city of Ravengro, the Whisper Woods, and the asylum of Saint. Mary of the Rose, where they will encounter a variety of allies and enemies, including undead creatures, cultists, and other supernatural threats.

Throughout the campaign, the players will face challenges such as battles against powerful foes, puzzles to solve, and moral dilemmas to confront. They will also uncover ancient secrets and learn about the dark history of Ustalav as they work to stop a powerful undead being known as the Carrion King from unleashing a terrible curse upon the land. The campaign includes a variety of challenges and plot twists that will test the players' skills and resolve as they work to uncover the truth and save Ustalav from disaster.