Water Myrmidon 03
Water Myrmidon 03 — The Encounter
The Undertow Executioner, a drowned soldier of bronze and tide · a boss your table can run with almost no prep. SRD 5.1-compatible.
Who Is Water Myrmidon 03
When the drowning of the great island-realm was sealed, its defenders did not all perish; some were remade. The Undertow Executioner is one such myrmidon, a soul poured into bronze and bound within a body of living tide. It was assigned to the collapsing tunnels and the submerged routes by which the desperate fled, and few of those it pursued ever reached open air. It does not speak, save for the hiss of water forced through a helmet that has no mouth. It does not tire, does not breathe, and cannot be drowned, for it is the drowning. Folk of the ruined coasts say the Executioner remembers each of its orders and none of its mercy, that it patrols the flooded undercity still, mistaking every living trespasser for a fugitive condemned long ago. To meet it in a flooded hall is to learn the slow certainty of the tide.
Run Water Myrmidon 03 in Sixty Seconds
- It is the tide, not a man. Immune to poison and every movement-locking condition, resistant to acid and fire and to nonmagical weapons. Don't waste prone/grapple/restrain on it, and don't expect fire to do much.
- Open from the water. Use Undertow Pursuit to swim to a back-line target without provoking, then mace it prone. Fight near water whenever you can.
- Kill-priority: the unswimming squishy. Anyone slogging through flooded terrain or stranded from the group is its prey; it ignores tanks to reach them.
- When bloodied, lean on Drowning Grasp. Lock down one PC each time it recharges (4d6 cold a turn, no breathing) and let allies pile on the helpless target.
- Three ways to run it: a lone tunnel-hunter dragging fugitives under; a flooded-lair sentinel with a Tidewarden holding the line; or a pair of myrmidons flanking a larger djinn-tier boss.
Water Myrmidon 03
Medium elemental, lawful neutral
CR 6 · 2,300 XP · GUIDELINEWatery Body. The myrmidon's lower half is a living column of water. It can move through a space as narrow as 1 inch wide without squeezing, and difficult terrain made of water or flooding does not cost it extra movement. While submerged or standing in water at least 1 foot deep, it has advantage on Stealth checks.
Undertow Pursuit. Signature. When a creature within 30 ft. that the myrmidon can see enters water or starts its turn in water, the myrmidon can swim up to its speed toward that creature without provoking opportunity attacks. If it ends adjacent, it may immediately make one melee attack against that creature.
Drowned Vigor. If the myrmidon takes acid or fire damage, the next attack it makes before the end of its next turn deals an extra 7 (2d6) cold damage as the breached water turns to slashing brine.
Actions
Multiattack. The myrmidon makes two attacks with its tidal mace.
Tidal Mace. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 15 (2d8+6) bludgeoning damage plus 7 (2d6) cold damage. If the target is Large or smaller, it must succeed on a DC 15 Strength saving throw or be knocked prone by the crashing blow.
Drowning Grasp (Recharge 5-6). The myrmidon engulfs one creature within 5 ft. in a coil of water. That creature must succeed on a DC 15 Strength saving throw or be restrained and unable to breathe until the start of the myrmidon's next turn, taking 14 (4d6) cold damage at the start of each of its turns while restrained this way.
Bonus Actions & Reactions
Tide's Recoil. Reaction. When a creature the myrmidon can see hits it with a melee attack, the myrmidon surges a wave outward; the attacker must succeed on a DC 15 Strength saving throw or be pushed 10 ft. away.
A faceless soldier sheathed in verdigris bronze, its torso fading into a churning pillar of glacial water that lifts it from a flooded floor, a long ceremonial mace glowing with cold light in its grip.
Water Myrmidon 03, Bound
Companion · acts on your initiative
Bound · GUIDELINEBulwark of the Deep (signature). Allies within 10 ft. of the Water Myrmidon 03 have resistance to fire damage, drawn into the cold mist that wreathes it.
Actions
Coral Maul. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 13 (2d8+4) bludgeoning damage plus 4 (1d8) cold damage.
Reactions
Surging Guard. When an ally within 5 ft. is hit by an attack, the Water Myrmidon 03 can impose disadvantage on that attack roll as a wall of water rises between them.
A heavier, broader myrmidon set as a living breakwater, content to anchor a line while sharper kin hunt the fleeing.
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 from the water with Undertow Pursuit so it reaches a soft target before the party reacts. If foes cluster on dry ground, lure them onto flooded tiles where it moves freely and they slog. Kill-priority: the lowest-AC caster trying to stay back.
Open by closing on an isolated PC and using Tidal Mace to knock it prone, then Drowning Grasp the moment it recharges. If clustered, wade into the front line and let Tide's Recoil punish each melee swing. Kill-priority: whoever lacks a swim speed or is standing waist-deep.
Run it with minions or in a flooded lair, never alone; pair it with a bigger threat that anchors the party while the myrmidon hunts stragglers. Open with Drowning Grasp on a frontliner, then pursue. Kill-priority: the most mobile skirmisher, dragged under before it can reposition.
Put Water Myrmidon 03 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 Water Myrmidon 03?
It's a Challenge Rating 6 elemental (2,300 XP) at its native Tier 2, tuned for a party of levels 5-10. The stat record also gives rescaled numbers for Tier 1 (levels 1-4) and Tier 3 (levels 11-15) so you can drop it into almost any flooded fight.
Can Water Myrmidon 03 be a companion or ally?
Yes. As a bound construct of water it makes a natural guardian; use the included Tidewarden, Bound companion block as a sturdier defensive ally that grants fire resistance and screens your party with walls of water rather than chasing kills.
Is it a boss on its own?
No. The Undertow Executioner is an add-on hunter, not a centerpiece. It shines pursuing stragglers in flooded terrain or flanking alongside a bigger threat such as a djinn or a true water elemental lord; run two or pair it with a lair to make a memorable encounter.
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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