- Its physical attacks cannot be blocked with a shield.
- It appears wreathed in lightning during its beam attack, but touching it will not hurt you.
- It can be cheesed by standing on the small stone bump between where it spawns and the door to the boss room. Wait there for it to stop moving, run forward and attack it, and then run back before it starts moving again.
- The balistae projectiles will also deal heavy damage to the sandworm, and is able to kill it in just a few strikes. Note that the projectiles will penetrate its body, striking the ground where the player stands. There is a small dip in the ground near the right side (facing the sandworm) of the boss door that will shield you from the projectiles but still allow them to strike the sandworm, his AI also seems to be unable to attack you from there.
This video shows where the sweet spot is that's mentioned in the previous paragraph.