Magworm

Magworm is described by its author as a test boss, the first of its kind in the project, and a worm built from magma cubes. It responds when a Magmatic Artifact is used to call it, and it attacks aggressively once present. The author states it has one unique trait, a damage rule that sets the damage it takes to a fixed value, so the fight depends on dealing damage from several sources at once. Piercing crossbow bolts and other multi-target weapons are noted as effective against it. Installation requires the server to run the mod; players may add it on their side for the fight, but joining clients need not have it.