Combat profile
Values below are the current Minecraft 26.3 / NeoForge defaults, before wave scaling and additional equipment. Existing server configurations can differ. Edit this mob's own registry entry in base stats and abilities; changes are not inherited from the ordinary Skeleton entry.
Building and ranged defense
Shares the Skeleton Builder's engineer construction and bow switching, using Nether Bricks by default. Bridging, towering, descending spiral staircases and engineer towers are enabled; stairing is disabled by default. It holds a hammer while building, stops for visible attack targets within 16 blocks, fires its first bow shot after 1 second and then every 2 seconds, and resumes construction when that target leaves range or sight.
It has dark bones, Wither Skeleton sounds and native fire immunity. Its movement hitbox is 0.7 blocks wide and 2.4 blocks high. It can use the one-block-wide ladder entrance to engineer towers without shrinking. For shared construction and repair, see terrain behavior.
On supported engineer-tower platforms it places red Nether Gravestones with Mob Griefing enabled, using the same left-of-center position and free-space checks as the normal Builder. These select NETHER mobs rather than UNDEAD mobs; see summoning and cleanup rules.
Four-block Wither aura
Once every 20 ticks (1 second), the aura applies Wither I for 100 ticks (5 seconds) to valid attack targets within 4 blocks. Staying nearby refreshes the effect; leaving the radius stops refreshes but the remaining effect can continue until it expires.
The aura respects attackability, allies, protected Versus teammates and valid invasion targets. It does not affect every living creature indiscriminately. This is a proximity effect, so avoid remaining within four blocks even when the Builder is occupied with construction.
Five-hit protective helmet
Its model helmet blocks five targeted player-melee or projectile head hits, wobbles on each blocked hit and disappears after blocking the fifth. Body hits remain damaging; explosions bypass this protection. The remaining hits are saved. Read the full helmet targeting and counterplay guide. The helmet leaves its 2.4-block collision height unchanged.
Counterplay
Fight from beyond the four-block aura radius and aim at the body to bypass its helmet. Fire and lava are ineffective against its native fire immunity. Destroy red gravestones promptly, prepare for their one extra summon on removal, and defeat the Builder to prevent replacement monuments. Breaking shared tower access alone may trigger repairs.
For current Minecraft 26.3 / NeoForge block mining and construction clearance, this Builder uses a 1× digging multiplier. The held tool, Efficiency, Haste, Mining Fatigue and water/air conditions determine the actual rate; construction headroom is cleared through the same timed process.
Drops
Uses the vanilla Wither Skeleton loot table: bones and coal, plus its conditional rare skull roll. Looting and player-kill conditions follow that table. It does not add Pigman Engineer pork or leather. An independent IM roll gives 1 Small Remnants with 25% probability; held or worn equipment follows normal equipment-drop rules.
Bones • vanilla table
Coal • vanilla table
1 Small Remnants • 25%Spawning and configuration
Selected by active wave themes or created with its dedicated spawn egg. The default spawn location is default: use the invasion's selected layer, normally ground, with the global spawn-layer rule taking precedence. To choose a per-mob layer, see spawn locations. Ordinary vanilla Skeleton replacement does not guarantee this specialist.
Default themes: ARMORED, RANGED, MIXED, RANDOM, RANDOMHELL, UNDEAD, SKELETONS, NETHER. Use theme editing to change selection. Wave cost is a budget value, not an egg crafting recipe.
With command permission: /give @s invmod:wither_skeleton_builder_spawn_egg. The icon here is the original vanilla family texture referenced by the mod item model; the egg has its own item and entity IDs. See Nexus equipment and team binding for egg spawns.
Related: Skeleton, Skeleton Builder, Wither Skeleton Builder, Skeleton Breacher.