Jekyll and Hyde
Jekyll and Hyde — The Encounter
The gentleman whose serum unchains the brute within · a boss your table can run with almost no prep. SRD 5.1-compatible.
Who Is Jekyll and Hyde
Recorded in the casebook of the steam-lit metropolis: a physician of brilliance and standing who, seeking to sever the savage half of man from the civilized, distilled a serum that did the opposite. The draught did not divide him — it loosed the thing he had buried. By daylight he keeps his manners, his cane, and his name; but the brass pump strapped between his shoulders feeds the change at a thought, and the gentleman's arm bursts into a hammering, leather-knuckled fist that caves doors and ribs alike. Witnesses describe two voices from one throat: one apologizing, one laughing. He is not possessed and not cursed — he is merely honest, at last, about what every man carries. Those who corner him learn that politeness is the mask, and the serum is the truth poured out. He cannot be reasoned with once the pump engages; only exhaustion of the body ends the rampage, and the morning after he weeps for it.
Run Jekyll and Hyde in Sixty Seconds
- Two stat lines, one mini. It starts as a polite Gentleman (no resistance, cane only) and becomes Hyde on a bonus action or after taking 20+ damage — decide up front whether you bait the party or transform on turn one.
- Open with the bait. Stay civil one round to draw melee in close, then Inject and turn the swarm against itself with Unchained Fury.
- Kill-priority: whoever clusters. Lead Serum Spray (Recharge 5–6) on a tight group, then Brute Fist to knock the caster prone and stand over them.
- When bloodied, go Reckless every turn. Trade AC for advantage — it's a brute, not a survivor; lean into the rampage.
- Three ways to run it: a tragic NPC who transforms mid-parley, a recurring rival who flees when bloodied, or a straight melee bruiser paired with a bigger boss — it is an add-on, not a solo.
Jekyll and Hyde
Medium humanoid (human, shapechanger), neutral evil
CR 6 · 2,300 XP · GUIDELINESerum of Two Selves. Bound to a steam-driven serum pump on its back, the creature exists in two states. In its Gentleman state it relies on the skull-cane and is unremarkable; the first time it takes 20 or more damage in a single turn, or as a bonus action, it injects the serum and becomes Hyde. While transformed it gains its resistance to nonmagical weapon damage and advantage on Strength checks and Strength saving throws. The transformation lasts until it drops to 0 hit points.
Reckless. At the start of its turn while transformed, it can gain advantage on all melee weapon attack rolls this turn, but attack rolls against it have advantage until its next turn.
Actions
Multiattack. The creature makes two attacks: one with its Brute Fist and one with its Cane (or two Cane attacks while in Gentleman state).
Brute Fist. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 18 (3d8 + 4) bludgeoning damage, and if the target is Large or smaller it must succeed on a DC 15 Strength saving throw or be knocked prone.
Cane. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) bludgeoning damage.
Serum Spray (Recharge 5–6). The serum pump vents a cloud of caustic alchemical mist in a 15-foot cone. Each creature in that area must make a DC 15 Constitution saving throw, taking 22 (5d8) poison damage on a failed save, or half as much on a success. A creature that fails is also poisoned until the end of its next turn.
Bonus Actions & Reactions
Inject (Bonus Action). If not already transformed, the creature injects the serum and becomes Hyde (see Serum of Two Selves).
Unchained Fury. Reaction, while transformed, when a creature within 10 feet hits it with a melee attack: the creature makes one Brute Fist attack against that creature.
A poised Victorian gentleman in top hat and waistcoat kneels upon a cobbled street, one hand resting on a skull-headed cane — while a brass serum pump valves and hisses on his back, his right arm swollen into a monstrous, vein-corded fist that betrays the brute clawing its way out.
Jekyll and Hyde, Bound
Companion · acts on your initiative
Bound · GUIDELINEPressure Build (signature). At the start of each of its turns the pump gains 1 pressure (max 5). It may spend all stored pressure to grant the creature it is bound to advantage on its next attack and +2 damage per pressure spent.
Actions
Piston Lash. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.
Reactions
Overpressure Vent. When the bound creature is reduced to half its hit points, the pump vents scalding steam: each creature within 5 feet takes 7 (2d6) fire damage.
A brass-and-copper apparatus of bellows, valves, and a single glowing serum reservoir, strapped to its bearer's spine and hissing with every heartbeat.
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 in Gentleman state — lean on the cane, parley, then inject as a bonus action the moment a PC commits. Once Hyde, charge the squishiest caster and use Brute Fist to knock them prone, then stand over them. Pair it with thugs or a cult handler so the party can't simply burst it down before it transforms.
Stay a gentleman one round to bait melee close, then Inject and go Reckless. Kill-priority is whoever clusters near it — lead with Serum Spray on a tight group, then Multiattack the prone target. Unchained Fury punishes anyone who trades blows, so it wants to be surrounded; feed it minions so the party can't focus-fire.
Run it as a brute lieutenant beside a bigger threat — an alchemist mastermind or a clockwork construct — not as the centerpiece. Open with Serum Spray into the cluster, transform turn one, and let Unchained Fury wall off the front line while the real boss casts. When bloodied it goes fully Reckless every turn; pair it with a lair or minions so a 4-PC party can't simply out-act it.
Put Jekyll and Hyde 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 Jekyll and Hyde?
Natively CR 6 (Tier 2, levels 5–10): AC 15, 127 HP, +7 to hit, save DC 15. Scaled stat lines are provided for Tier 1 (~CR 2) and Tier 3 (~CR 11) — the traits stay identical, only the numbers move.
Can Jekyll and Hyde be a companion or ally?
Yes, with a leash. As a Gentleman he's a charming physician ally — but his Serum of Two Selves means any hard hit can flip him to Hyde mid-scene, attacking friend and foe alike. Run him as a volatile asset, not a reliable bodyguard; the included Serum Pump can be the device a clever party learns to disable.
Is he solo boss material?
No. He's a hard-hitting brute add-on, not a centerpiece — he lacks legendary actions, so a four-PC party out-acts him alone. Pair him with minions, a lair, or a smarter mastermind and let Unchained Fury and Serum Spray make the front line miserable.
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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