Found in two locations in Catacombs of Carthus. One rolls back and forth along a large, open staircase close to the entrance of the level, while the other rolls back and forth along a narrow hallway next to the Catacombs of Carthus bonfire.
- It only stops once the Skeleton with a pointy hat is killed. Upon killing this skeleton, the boulder will break when it next smashes into a wall
- Can damage and kill enemies.
- When the first boulder breaks, it will leave behind an Undead Bone Shard
- When the second boulder breaks, it will leave behind a Lesser Crab. The purpose of this crab is currently unknown.