Mythic Clockwork Leviathan

Mythic Clockwork Leviathan CR 15/MR 6

XP 51,200
N Huge construct (clockwork, mythic)
Init +15MF; Senses darkvision 60 ft., low-light vision; Perception +0


AC 35, touch 15, flat-footed 28 (+5 Dex, +2 dodge, +20 natural, –2 size)
hp 188 (16d10+100)
Fort +5, Ref +12, Will +5
DR 10/adamantine and epic; Immune acid, fire, construct traits; Defensive Abilities immunity to magic (see orichalum alloy)
Weaknesses vulnerable to electricity


Speed 30 ft., swim 60 ft.
Melee bite +27 (2d6+13), 2 slams +27 (1d8+13 plus grab)
Space 15 ft.; Reach 15 ft.
Special Attacks breath weapon (60-ft. line, 12d8 fire damage, Reflex DC 18 for half, usable every 1d4 rounds), mythic power (8/day, surge 1d8), swallow whole (2d8+19 slashing damage plus 2d6 fire damage, AC 20, 18 hp)


Str 37, Dex 20, Con —, Int —, Wis 11, Cha 1
Base Atk +16; CMB +31 (+35 grapple); CMD 48 (54 vs. grapple, can’t be tripped)
Feats Extra Mythic PowerMF, Improved Initiative MF, Lightning ReflexesMF
Skills Stealth +9 (+13 in water), Swim +21; Racial Modifiers +12 Stealth (+16 in water)
SQ electrical dampeners, fortification, ionic meltdown, orichalum alloy, perpetual motion, serpentine slither, swift reactions


Breath Weapon (Su)

A clockwork leviathan’s breath weapon is a powerful jet of scorching steam—it functions equally well above and under water.

Electrical Dampeners (Ex)

When it is targeted with an electricity effect dealing more than 10 points of damage, a mythic clock leviathan automatically expends one use of its mythic power to suppress its vulnerability to electricity and gain electricity resistance 10 until the beginning of its next turn.

Grind (Ex)

A clockwork leviathan deals an additional 1d8+16 points of slashing damage when it makes a successful grapple check because of the myriad twisting gears and churning pistons that make up its jagged underbelly.

Ionic Meltdown (Ex)

When a mythic clockwork leviathan is brought to 0 hit points, its ionic core is breached it explodes in a mass of heat, steam, and shrapnel, dealing 8d6 points of fire damage and 8d6 points of slashing damage to all creatures in a 60-foot burst (DC 23 Reflex half ). In addition, creatures failing their saves are exposed to full fury of the ionic energies being released and are blinded and stricken with a wasting disease equivalent to bubonic plague (as described in the Pathfinder Roleplaying Game Core Rulebook). The save DC is Strength-based.

Orichalum Alloy (Ex)

Mythic clockwork leviathans were mostly constructed by antediluvian builder races and are constructed of strange metal alloys little known in the modern world. Their metallic parts are not subject to rust or corrosion, nor are they subject to magical manipulation.

A mythic clockwork leviathan is immune to acid and also gains immunity to magic like a golem, ignoring the effects of any spell or spell-like ability that allows spell resistance, except for fire and electricity effects. A clockwork leviathan is vulnerable to electricity damage. Heat energy, on the other hand, is absorbed to power their ionic thermal engines, even tapping into minute variations in the ambient environment to replenish its stores. A mythic clockwork leviathan targeted with a fire effect heals 1 point of damage for every 3 points of damage the attack would normally have dealt.

Perpetual Motion (Ex)

A mythic clockwork leviathan never needs winding and adds its mythic tier to its CMD against grapple combat maneuvers and on saving throws against effects that would cause it to become entangled or staggered.

Serpentine Slither (Ex)

A mythic clockwork leviathan can squeeze through spaces small enough to admit a Medium-sized creature without squeezing. In addition, it can expend one use of its mythic power in order to enable it to move both before and after taking a standard action, as long as its total movement does not exceed its speed; this functions like the Flyby Attack feat but does not require the creature to be flying. Alternatively, it can expend one use of its mythic power to perform a standard action and then use the withdraw action as a move action, moving up to its speed.

Swallow Whole (Ex)

A clockwork leviathan’s interior is filled with injurious grinding gears and superheated water—in addition to taking damage, a swallowed creature must hold its breath or risk drowning as long as it remains inside a clockwork leviathan’s “stomach.” Clockwork leviathans are equally capable of functioning on land and in water. Sailors who are haunted by the memories of these treacherous machines need not exaggerate their yarns, for the reality of an aquatic construct such as this holds enough terror in its story for even the hardiest of seafarers.


Environment any
Organization solitary or pod (2–4)
Treasure none

This massive, eel-like dragon has two webbed talons. Its tail ends in large and powerful-looking flukes.

A clockwork leviathan’s numerous metal plates and links are made of such resilient material that they never rust, even after long exposure to the briny sea waters that leviathans often patrol. Clockwork leviathans are 25 feet long and weigh just over 3 tons.

As a constructed being, a clockwork leviathan doesn’t eat, breathe, drink, or sleep. If it is not wound regularly, it becomes inert until it is wound again.

Section 15: Copyright Notice

Mechanical Monsters © 2023, Legendary Games; Authors: Jason Nelson, Tom Phillips, Mike D. Welham, Matt Goodall, Alex Riggs, Matt Daley.

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