One of the largest monsters in Lothric, the Carthus Sand Worm is enormous and covered in a rock-like shell. Despite its large size, it can move extremely quickly.
The sand worm is a formidable opponent, using a lightning beam to take out targets at a distance, while the protrusions on its shell are combined with its rapid movements to deal with melee attackers.
The ballista tower will cover the area around the sand worm and can damage it if the player stands behind a small outcropping of rocks located in front and to the left of the entrance to the Old Demon King's boss arena. Neither the worm or the ballista will damage the player there, and given enough time, the arrows will strike the worm as it writhes around trying to reach the player.
Undead Bone Shard