Especially Nasty – Murder Mollusk

I’ve dug up this beauty from the depths of cloud storage (or should it be heights?), a kaiju boss fight. I mostly share it now because of all the titles the creature has.

A monstrous slug five meters tall and twenty long, with scythe-like claws as long as a man, it crawled out of the sea and headed straight for the nearest city. Seagulls fell from the skies in its wake, burned by its foul miasma, trees wilted as it passed. All that stood between it and civilization was a group of plucky heroes manning a defensive wall and an arcane McGuffin Vibrational Disruptor they’d just rescued planted on top of it.

Murder Mollusk

Polyp of Pestilence, Sovereign of Slime, Ruler of Rot, Crustacean Czar, Tarnishing Tyrant

Huge 8th level wrecker [BEAST]

Initiative: +11

Murderous bite +16 vs AC – 75 damage, 30 acid damage and the mollusk grabs the target if it’s not already grabbing a creature.

Miss: 20 acid damage.

Scything claws +16 vs AC (2 attacks against nearby enemies) – 50 damage.

Natural even hit or miss: the target pops free of all enemies and is flung away.

Miasma: When a creature is engaged with the mollusk at the start of its turn, it takes acid damage equal to 9 times the escalation die.

Flesh of Chaos: Whenever the mollusk is hit by a natural odd number attack, it spawns a chaos glorp nearby. Whenever the mollusk is critically hit or staggered for the first time, it spawns a chaos beast nearby (both creatures are found in the Bestiary). If the attacker is engaged with the mollusk, the spawned creature immediately engages them.

Nastier Specials (duh):

Bejeweled mollusk: The mollusk has glowing stones embedded in its chitinous hide. When an enemy misses with an attack against the mollusk, that enemy chooses one: it takes 10 acid damage; OR one piece of its non-magical equipment (something useful, but player’s choice) melts. Adjust skill checks or stats accordingly.

Steaming body: The mollusk’s foul stench obscures the air around it. Ranged attacks against the mollusk take a -2 penalty, or a -4 penalty if the attacker is far away.

AC 24

PD 22    HP 420

MD 18

Everything Rots

If the Vibrational Disruptor is not operational at the start of the mollusk’s turn, decrease the escalation die by 1 and destroy one fortification or war machine.

Vibrational Disruptor

A sphere of concentric rings creating a teeth-shattering hum when they resonate. d6, d8, d12 and d20 symbolize the speeds at which they rotate. A character operating the machine can spend a quick action to activate it for the turn to roll all the dice. Another quick action can be used to adjust the settings and re-roll any of the dice. If at the end of a round any dice are common denominators of others (e.g. 4 and 8), everything in the fight takes those dice in damage. 1s don’t count.


Two ballistae are mounted on the wall. The character operating a ballista can use the following attack:

R: Anti-kaiju projectile +14 vs AC (one nearby or far away enemy) – 50 damage.

Limited use: the ballista must be reloaded between shots, which takes a standard action. Another character can do this.

If you have uncanny memory for monster abilities, you’ll be able to recognize a remorhaz deep within the slimy exterior of the Murder Mollusk. I’ve used it as a foundation before adding abilities to make it more of a boss monster. From what I recall, it showed up some distance away, giving the party a couple of rounds to shoot at it. There most likely was a sahuagin herald running ahead, whose main purpose was to announce all the titles of its god. And, despite being 4 levels below it, a defensive ability and other threats present on the battlefield, the party murdered the Murder Mollusk in about 3 rounds.

At the time, it prompted the post on boss decay, an abstract and slight of hand way of preventing abrupt death of our beloved bosses. In retrospect, I really shouldn’t have been surprised. 13th Age doesn’t have Solo monsters of D&D 4e, which were meant to stand up to a party of 5 on their own. They most often couldn’t due to action economy among other things, but at least the concept was there. At most, 13th Age has triple-strength (or Huge) monsters, which, unsurprisingly, pose a threat to at most 3 characters.

The implication is clear enough: don’t have a sole boss monster, add underlings of some sort to spice up the fight. And I did! But players can prioritize, save up their most powerful abilities for the boss, and squash it like a slug. Which isn’t exactly a problem, they feel like big damn heroes. But, y’know, I’d like my monstrosity to feel like a big damn threat before it dies. Not to mention the quick fight making the McGuffin we’d spent several sessions restoring almost meaningless.

Here, then, are a few alternative ideas to prolonging the average lifetime of a boss.

Shielding Minions

The boss gains resist all damage X, where X is twice the number of its mooks present on the battlefield. Start the fight with 10 mooks, and/or add a few every round or on some trigger, whatever suits the situation. Give the PCs a reason to not just nuke the boss.

Vulnerable While Charging Up

While the escalation die isn’t even, the boss’ defenses increase by 3. While it is even, they decrease by 2 instead. Of course, it makes a nasty attack while the escalation die is even. For bonus points, present an opportunity for PCs to hide from this attack instead of hitting the vulnerable boss. Tactical choices! And don’t forget to add other enemies to the fight so PCs have something to do while waiting for the boss to open up again.

Truly Enormous

An old idea of mine (I’m sure others have thought of something similar too), breaking up the gigantic enemy into several sub-creatures that have their own hit points, do their own attacks or grant it traits. A fight against such a boss is likely to be much more brutal: instead of the abstraction of damage, you’re chopping off its limbs. This is a much more involved approach as it likely requires designing everything from scratch. Guess writing up one such enormous boss monster will be my next project.

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