Marrowfiend Ossark
Marrowfiend Ossark — The Encounter
Crowned revenant who feasts on the marrow of the slain · a boss your table can run with almost no prep. SRD 5.1-compatible.
Who Is Marrowfiend Ossark
In the dead lands the common folk name the Mortisbane Revenants, none is more feared than Ossark the Marrowfiend, who was a crowned captain in life and a butcher in death. The grimoires tell that he bargained for victory and was paid in famine: his host starved upon the field, and he learned to feed upon the marrow of his own fallen to keep marching. The hunger never left him when the grave took him. Now he rises in gold-chased armor, the horns of his crown curling like a feast-day beast, and where he walks the buried wake to follow. He does not hate the living; he is simply always starving, and the cracking of their bones is the only music that quiets the gnawing within. Knights who fall before his cleaver are not merely slain. They are emptied, and what little of them remains is set grinning upon his shoulders to witness the next harvest.
Run Marrowfiend Ossark in Sixty Seconds
- Feed loop Always swing at the most-wounded target first. Marrow Feast heals Ossark 10 and grants advantage when he hits a creature already below half, so he snowballs against a hurt party.
- Open with the cleaver on the squishiest or most-damaged PC, both to feed and to shut off their healing until your next turn.
- Recharge gate Hold Dirge of the Hungry Dead until two or more living creatures sit within 15 feet, then drop it for AoE necrotic and self-healing.
- Kill-priority targets the party healer first; the Marrow-Cleaver already prevents healing, so dropping the healer starves the party of recovery.
- Three ways to run him as a relentless marrow-hungry duelist who chases the weakest, as a healing engine anchoring a horde of risen dead, or as an elite lieutenant flanking a larger flagship boss.
Marrowfiend Ossark
Medium undead, neutral evil
CR 6 · 2,300 XP · GUIDELINEMarrow Feast. Signature. The first time on each of its turns that Ossark reduces a living creature to 0 hit points or strikes a creature that is already below half its hit points, Ossark cracks the victim's bones and drinks the marrow: it regains 10 hit points and gains advantage on its next attack roll. While it has fed this turn, its cape and crown blaze with cold light.
Undead Fortitude. If damage reduces Ossark to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, it drops to 1 hit point instead.
Actions
Multiattack. Ossark makes two attacks with its Marrow-Cleaver.
Marrow-Cleaver. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6+4) slashing damage plus 7 (2d6) necrotic damage. A creature that takes necrotic damage from this attack cannot regain hit points until the start of Ossark's next turn.
Dirge of the Hungry Dead (Recharge 5-6). Ossark loosens a wailing dirge. Each living creature within 15 feet must make a DC 14 Constitution saving throw, taking 18 (4d8) necrotic damage on a failed save, or half as much on a success. Ossark regains hit points equal to half the total necrotic damage dealt.
Bonus Actions & Reactions
Bone Bulwark. Reaction. When a creature Ossark can see hits it with an attack, Ossark raises a shield of jutting bone and adds 3 to its AC against that attack, possibly causing it to miss.
A skull-faced warlord in gilded horned plate and a tattered crimson cape, hefting a notched cleaver-blade as long as a man, his rotted body studded with the grinning skulls of those whose marrow he has drunk.
Marrowfiend Ossark, Bound
Companion · acts on your initiative
Bound · GUIDELINEMarrow-Touched (signature). When Cael deals damage with a melee attack to a creature below half its hit points, Cael regains 5 hit points.
Actions
Bone Glaive. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 9 (1d10+4) slashing damage plus 4 (1d8) necrotic damage.
Reactions
Take the Blow. When an ally within 5 feet is hit by an attack, Cael steps in and takes the damage instead.
A half-rotted standard-bearer who marched beside Ossark to the last and was hollowed out to march forever, glaive lashed to a fleshless hand.
Guideline numbers — formula-tuned and read from the miniature's design, not yet table-proven. Tell us how it ran in the comments.
How It Fights — by Tier
Same creature, scaled threat. The traits never change; only the numbers move.
Open by closing the gap and swinging at whoever already looks hurt so Marrow Feast triggers and heals him. Hold the Dirge until two or more PCs are clustered within 15 feet. Pair him with a swarm of weaker skeletons to soak attacks.
Open by charging the lowest-HP target to feed and heal off Marrow Feast. Save Dirge for when the party bunches up, then heal off the necrotic. Kill-priority: the healer, since his Marrow-Cleaver already blocks healing. Pair him with a bigger flagship boss or a lair of risen dead, not as a lone fight.
Open into the squishiest front-liner to feed turn one. Spend Bone Bulwark on the hardest-hitting reaction-worthy strike. He is an elite add, not a solo: run him alongside a larger threat or a swarm of minions, feeding and healing while the bigger menace presses the party.
Put Marrowfiend Ossark on the table
Download the presupported STL and run the fight tonight — the model, and the encounter that comes with it.
Get the STL on MyMiniFactory →Clay Cyanide Companion Rules v1
How a bound creature acts
- A companion acts on its owner's initiative, immediately after the owner.
- It uses the Companion block above — roughly ×0.6 HP and damage, no recharge abilities, and at most one reaction trait.
- It moves freely; it takes its Action only while its owner is conscious.
- At 0 HP a companion is broken, not dead — restored on a long rest unless your table rules otherwise.
Original Clay Cyanide material © Clay Cyanide LLC — explicitly not the non-SRD official sidekick rules.
Questions, Asked at the Table
What CR is Marrowfiend Ossark?
His home build is CR 6 (2,300 XP) for a party of levels 5-10, with AC 16 and 120 HP. The sheet also includes a CR 2-style build for levels 1-4 and an elite CR 11-style build for levels 11-15; the traits stay identical and only the numbers move.
Can Marrowfiend Ossark be a companion or ally?
Ossark himself is a centerpiece adversary, not a player companion. The block instead provides Cael the Hollow, his bound standard-bearer (AC 14, 65 HP), as a ready-made ally or a second threat with a self-healing glaive and a Take the Blow reaction.
Is Marrowfiend Ossark a solo boss?
No. He has no legendary actions and only a single defensive reaction, so a full party will out-act him. Run him as an elite add-on: pair him with a bigger flagship boss or a lair of risen dead rather than as a one-on-four solo fight.
Tell Us How It Ran
This work includes material taken from the System Reference Document 5.1 ("SRD 5.1") by Wizards of the Coast LLC and available at dnd.wizards.com/resources/systems-reference-document. The SRD 5.1 is licensed under the Creative Commons Attribution 4.0 International License available at creativecommons.org/licenses/by/4.0/legalcode.
Clay Cyanide Miniatures is not affiliated with, endorsed, sponsored, or specifically approved by Wizards of the Coast LLC. This content is compatible with the fifth edition of the world's most popular fantasy roleplaying game. Companion rules, lore, names, and original mechanics © Clay Cyanide LLC.
Technical Specifications
32mm, 75mm
STL, Pre-supported STL
Standard or ABS-like resin, 0.05mm layer height
Yes — ready to print, optimized supports included
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