Yamm
Yamm — The Encounter
Canaanite Lord of Sea and primordial Chaos, the Roaring Deep · a boss your table can run with almost no prep. SRD 5.1-compatible.
Who Is Yamm
Before the dry lands were named, the sea was a hunger, and the hunger had a voice: Yamm, called Judge River and Lord of the Deep by the people of Ugarit. He is the firstborn of chaos, the roaring tide that demands tribute and tolerates no shore. In the old tablets the storm-rider Baal alone could break him, and even then the sea was not slain but only bound, ever rising again with the equinox swells. Where Yamm passes, harbors choke with brine, wells turn salt, and sailors hear their own names called from beneath the hull. He does not bargain so much as flood: every promise sworn to him is a promise to drown. To raise him is to invite the abyss to remember its old claim on the world, for the sea keeps no covenant it cannot dissolve. Those who would treat with him must speak above the water, and never look down.
Run Yamm in Sixty Seconds
- Aura first Tide of Chaos makes a 20-ft. ring of difficult water around Yamm every round - drop it the moment combat starts so the party fights on his terms.
- Open with Drowning Surge if the party is clustered, the 30-ft. cone scatters and prones them; otherwise grapple the front-liner and hold position.
- Kill-priority anyone leaving the water - punish movement with the Undertow reaction, and chase fleeing casters who escape the aura.
- When bloodied Yamm fights to drag a grappled PC into deep water where they risk drowning; he never retreats onto dry land.
- Three ways to run it as a lone chaos-tide boss with minions, as a control add-on beside a kraken or storm-god, or as the drowning heart of a sinking-temple lair.
Yamm
Large fiend (demon), chaotic evil
CR 6 · 2,300 XP · GUIDELINEAmphibious. Yamm can breathe air and water.
Tide of Chaos. Signature. The ground within 20 feet of Yamm is difficult terrain of surging water for any creature that isn't him. A creature that ends its turn there must succeed on a DC 14 Strength save or be pushed 10 feet away from Yamm and knocked prone.
Actions
Multiattack. Yamm makes two Crashing Coil attacks, or one Crashing Coil attack and casts a spell.
Crashing Coil. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 14 (2d8+4) bludgeoning damage plus 9 (2d8) cold damage, and the target is grappled (escape DC 14) if it is Large or smaller.
Drowning Surge (Recharge 5-6). Yamm exhales a torrent of seawater in a 30-foot cone. Each creature there makes a DC 14 Dexterity save, taking 22 (5d8) cold damage and being pushed 15 feet away and knocked prone on a failure, or half damage and no push on a success.
Bonus Actions & Reactions
Undertow. Reaction. When a creature within 10 feet starts to move away from Yamm, he may make a Crashing Coil attack against it.
Coiled in a column of living seawater, this serpent-god rears with a crown of horns and a mane of churning foam, his scaled body lit from within by cold abyssal light.
Yamm, Bound
Companion · acts on your initiative
Bound · GUIDELINECoil-Sworn (signature). Yamm, the sea-drake of the deep, can breathe water and has advantage on saves against being moved or knocked prone while within 15 feet of an ally.
Actions
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 11 (2d6+4) piercing damage plus 4 (1d8) cold damage.
Reactions
Riptide Pull. Reaction. When an ally within 20 feet is hit by a melee attack, Yamm lashes the attacker: it must succeed on a DC 13 Strength save or be pulled 10 feet toward Yamm.
A lithe sea-drake spawned from the same chaos-froth, it circles its master like a living riptide.
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 with Drowning Surge to scatter the clustered party, then grapple the front-liner with Crashing Coil and drag them into the deep. Kill-priority is anyone trying to flee the water - punish them with Undertow. Pair Yamm with a swarm of aquatic minions so the party can't out-action him.
Lead with Tide of Chaos terrain to break the party's formation, then open on the heaviest hitter with a grapple and hold them while Drowning Surge recharges. Focus the healer once it steps clear of allies. As an add-on to a flagship storm-god or kraken, Yamm bottlenecks melee in his churning aura while the bigger threat closes.
Open by flooding the field with Tide of Chaos, then alternate Drowning Surge and double grapples to keep two PCs locked underwater. Kill-priority: ranged casters who can hit from beyond his aura. Pair him with a larger leviathan boss or a drowned-temple lair so Yamm controls space while the centerpiece deals the killing blows.
Put Yamm 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 Yamm?
Yamm is natively CR 6 (Tier 2, levels 5-10), a Large fiend built around battlefield control through water and grappling. The stat block also scales to CR 2 (Tier 1) and CR 11 (Tier 3) using the same traits and actions with adjusted numbers.
Can Yamm be a companion or ally?
Yamm himself is a chaotic-evil adversary, but the record includes Tannin, Bound - a sea-drake companion (AC 14, 76 HP) that can serve as a player ally or a secondary threat the DM fields alongside Yamm.
Is Yamm a solo boss?
No. Yamm is an add-on controller, not a centerpiece - he lacks legendary actions, so a full party will out-act him alone. Run him with minions or beside a bigger flagship threat such as a kraken, leviathan, or storm-deity.
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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