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Bonemass is the third boss of Valheim. It appears as a gigantic humanoid mass comprised of toxic ooze, mud and skeletal remains likely absorbed from nearby tombs situated close to its altar.


Bonemass' Forsaken Altar.

Bonemass' Forsaken altar is located in Swamps. Its location can be found when visiting Sunken Crypts and sometimes ruined structures, where a Vegvisir will reveal its nearest summoning location on the map.

It is summoned by placing 10 Withered bone.png Withered bone in its Forsaken altar in Swamps. Like all bosses, Bonemass can be resummoned as many times as desired, provided the required materials are met.  

Attacks and abilities

Main article: Boss Strategies

Bonemass has an environment aura that forces raining which means pulling him from the swamp can't be used to remove Wet.


A close-range swipe at a player dealing up to 80 Blunt and 30 Poison damage to players, and 1000 Chop and 1000 Pickaxe damage to any trees or rocks hit.

Area of effect

Bonemass will charge up with a thick green cloud before releasing a wave of poisonous ooze, poisoning everything in a wide range around him (100 Poison damage). This is signaled when he leans backwards. The poison cloud persists for several seconds and will continuously refresh the poison duration on any player that stays inside.


At intervals, Bonemass will reach into his armpit to throw out a glob of goop. This is never directed at a player, and will spawn up to 4 random monsters (skeletons and/or blobs) where it lands. No more of a creature type will be spawned once 8 of that type are already present.


Defeating Bonemass provides the player with a Wishbone, which is allows the player easily locate Silver Deposits beneath the surface of the Mountain.


Item 0 Star
Bonemass trophy.png Bonemass trophy 1
Wishbone.png Wishbone 1 per player

Forsaken power

See Bonemass' power.


Defeating Bonemass affects the following events for that world:

  • Disables: Draugr and Skeleton "A foul smell from the swamp".
  • Enables: Blobs and Oozers "A foul smell from the swamp".
  • Enables: "Skeleton Surprise".
  • Enables: "A cold wind blows from the mountains" (if Moder hasn't been defeated).
  • Enables: "There's a smell of sulfur in the air" (if a Surtling has died).
  • Enables: "You are being hunted".
  • Enables: "You stirred the cauldron" (if a Bat has died)

Note: Two of these events unlock flying enemies that will be uninhibited by base walls and will attack tame animals. For example, bats will quickly wipe out any outdoor tame boars (if the player has them), most likely before the player can swat them all. Therefore, in order to protect any rare animals (such as a 2-star Boar), it is advisable to build a secure indoor barn area before undertaking Bonemass.

Creature spawning

Defeating Bonemass unlocks Skeletons to spawn at night in the Meadows, Black Forest, Swamp (additional), Mountain and Plains. They can only have 0 stars.



  • Bonemass has undergone a model change since Valheim's release.
Creatures (View Template)
Passive CrowDeerFishGullLeviathan
Meadows DeerBoarNeckGreyling
Black Forest GreydwarfGreydwarf bruteGreydwarf shamanSkeletonGhostRancid remainsTroll
Swamp SkeletonDraugrDraugr eliteLeechBlobOozerSurtlingWraithAbomination
Mountains WolfDrakeFenringStone GolemBatUlvCultist
Plains DeathsquitoFulingFuling BerserkerFuling shamanGrowthLox
Ocean LeviathanSerpent
Ashlands Surtling
Deep North
Boss EikthyrThe ElderBonemassModerYagluth
Spawners & Boss Minions Rancid remainsBody pileRoot
NPC ValkyrieHuginHaldorHalsteinOdin