Marrowking: find the spine.

What it is

Marrowking is a whale skeleton on four flipper-legs: a skull the length of a boat, twelve vertebrae each with its ribs, and a tail of woven worms. The worms are its muscle and they rebuild any bone that breaks. Only one vertebra, its spine, can be hurt. That is the one with a red heart glowing in its ribs, and it is a different vertebra every time Marrowking rises. It is based on whale falls, where a dead whale feeds life on the sea floor for decades, including worms that eat bone.

Where and when it comes

• On the floor of the Wide Blue open ocean and the Hadal Rift trench.
• It rises where a whale has fallen. If a whale dies in your world and you are swimming within 140 metres of the spot, its bones can climb back out of the sea bed.
• Failing that, it may rise 32 to 46 metres from a swimmer in the deep sea, where the water is at least fourteen metres deep.
• It goes only after people in the water. A crew on a ship's deck high above is not its prey.
• After one is slain, another cannot come for about 30 minutes. The Codex hint is "Bones walking on the sea floor".

Stats

Thing	Value
Health	1100 (only the spine takes it)
Bones	12 vertebrae, 70 strength each
Rebuild time for a broken bone	14 seconds, 9.8 when enraged
Walking speed	3.2 m/s, 30 per cent faster when enraged
Jaw bite	24 damage (25 per cent more when enraged), 0.7 second wind-up, reach about 6.5 m, about every 3.5 seconds
Tail sweep	16 damage, 0.8 second wind-up, reach 7 m, about every 6 seconds
Worm cloud	A boiling column of worms 7 m wide and up to 22 m high for 5 seconds, 3 damage every half second, about every 11 seconds
Signature: Bone Rain	Three marks round you one after another, 2.4 m wide, 10 damage, about 1.1 seconds of warning, about every 12 seconds
Wait before another comes	About 30 minutes

How the fight works

1. Rising. It climbs out of the sea bed over about four seconds, silt pouring off its bones.
2. Hunting. It walks along the floor after you, and rears its head up toward you if you swim high above it.
3. Bite, sweep, cloud. It bites anyone at its jaws, sweeps its tail at anyone by its back end, and every few seconds sends a cloud of worms boiling up from its spine at whoever is above it.

Below half health it is enraged: faster, quicker to attack, and its bones are rebuilt sooner.

Breaking it

• Blows on a normal bone cost Marrowking nothing. They only wear the bone down: after 70 damage it breaks and the worms start rebuilding it.
• The skull takes no damage at all.
• Only the spine, the vertebra with the red glow, hurts it, at normal damage.
• Break five bones at once and it collapses on the floor for about five and a half seconds. While it is down the spine takes two and a half times as much damage.

The plan is to break five bones quickly (a group helps), then pour everything into the spine while it is down.

Tips

• Find the spine first. The red glow shows in the ribs.
• The worm cloud starts at the spine and climbs. Swim sideways out of its column; do not try to go over it.
• Stay off its jaw's front and the tail's end when the wind-up starts.

What it drops

Drop	Amount
Bone pieces	28 to 41
Bone meal pieces	12 to 19
Abyssal pearls	1 to 3
Gold pieces	3 to 6
Trophy	Marrowking Bone-Crown

← Back to the wiki · Last updated 25 October 2026. Mantlenaut is in alpha, so things change.