Kaiju for Dungeons and Dragons: Metallor, The Iron Mountain

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The Dungeons & Dragons kaiju train keeps rolling! What’s a kaiju story without some mechanical monsters? This week’s project is Metallor, a horrific fusion of magic, machine, and bone. Like Hurriking and Mantisma, Metallor takes inspiration from a Toho Studios kaiju, this time it’s Mechagodzilla (specifically Kiryu) with a hint of Gurren Lagann thrown in. Enjoy!

Metallor, The Iron Mountain

Colossal construct (kaiju), lawful good

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Artwork: Godzilla X Mechagodzilla Concept Art, Property of Toho Studios

“The Empire attempted to create their own Hurriking. When will man learn?” – Brother Tino’s Chronicle of Greater Kaiju

When kaiju began to appear in Yamatai, it was inevitable that mankind would attempt to create their own. After locating the colossal skeleton of the first Hurriking, Emperor Larondam commissioned in secret a cadre of mad artificers to begin a blasphemous experiment. Their directive: Create a monster that would serve Yamatai. The work of several successive generations finally bore fruit: a three hundred foot tall fusion of bone, metal, and magic.

Metallor was crafted to be controlled via a psionic resonance chamber located in the construct’s head, but was given a small amount of autonomy to reduce mental stress on the controller. Upon first activation however, Metallor’s artificial intelligence assumed full control, frying the mind of the controller. The iron colossus fled from the secret laboratory of its creation and made a home for itself in an expansive mountain cavern in the north of Yamatai.

Brothers in Stature. Metallor stands over three hundred feet tall, roughly the same height as Hurriking. Given that Metallor was constructed from the first Hurriking’s skeleton, this is not surprising.

Metallic Idol. Upon Metallor’s activation and escape, the artificers that shepherded its creation abandoned service to Yamatai’s Emperor and dedicated themselves to the artificial god. They named themselves the Order of the Iron Mountain and work to maintain, repair, and upgrade Metallor between its combat excursions.

A Mind of Its Own. The accidental emergence of a sentient mind in Metallor removed capability for the construct to be controlled by a pilot. It still considers protection of Yamatai to be its mission, but it refuses to take orders from the Emperor and decides for itself what threats and affairs it will interfere with. It appears to have a strong moral code, but the Order of the Iron Mountain refuse to reveal details.

Family Ties. Hurriking and Metallor have a relationship that can almost be compared to feuding siblings. The two have clashed many times, but Metallor always relents from killing its organic rival. It has also defended Hurriking from powerful enemies on several occasions, but still never hesitates to engage its ‘brother’ to protect Yamatai.

Variant: Elemental Upgrade

As an artificial construct, Metallor’s weaponry can be modified by its followers. Its Ice Stinger Barrage, Lightning Ripper, and Supernova Eruption attacks can have their damage types changed to any of the following: Cold, Fire, Force, Lightning, Radiant, or Thunder.

  • Armor Class 26 (natural armor)
  • Hit Points 650 (35d20+300)
  • Speed 150 ft., Fly 150 ft.

25 (+7) 12 (+1) 30 (+10) 16 (+3) 15 (+2) 15 (+2)

  • Saving Throws Con +9
  • Damage Resistances acid, radiant, fire, thunder, bludgeoning, piercing, and slashing from non-kaiju attacks
  • Damage Immunities cold, necrotic, poison, lightning
  • Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
  • Senses darkvision 200 ft., passive Perception 10
  • Challenge 30 (155,000 XP)

Kaiju Hide. Any time Metallor is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 5, Metallor is unaffected. Additionally, Metallor is immune to spells of 6th level or lower. It has advantage on saving throws against all other spells and magical effects.

Massive Combatant. Metallor’s Bite and Drill Claw attacks can hit all creatures within a 25 foot square. All creatures in the area whose AC is equal to or lower than its attack roll are affected.

Gigantic Flier. Metallor’s flight speed is unaffected by weather conditions.

Legendary Resistance (3/Day). If Metallor fails a saving throw, it can choose to succeed instead.

Limited Power. As an artificial kaiju, Metallor runs on limited reserves of power. When deployed from its temple, Metallor has three hours of activation time before it must return to restore its energy. If it finds itself unable to return, it shuts down to an inert state, unable to attack, move, or defend itself, although its AC remains the same. If Metallor is hit by lightning damage, ten minutes of its activation time are restored.

Siege Monster. Metallor deals double damage to objects and structures, plus 20 (4d10) damage if Metallor has activated Spiral Drive.

Spiral Drive. As an action, Metallor can activate its Spiral Drive, which turn its claws into spinning drills. This lasts for 2d6 rounds. While Spiral Drive is activated, Metallor has a burrowing speed of 150 ft.

Titanic. Because Metallor is so massive, all forms of difficult terrain, except for mountains, don’t hinder its movement. Huge or smaller creatures can move through any squares occupied by Metallor, or vice-versa. Creatures that are Large or smaller can’t provoke opportunity attacks from Metallor. It is possible for a Huge or smaller creature to climb Metallor—this requires a successful DC 20 Strength check.


Multiattack. Metallor makes four attacks: one with its bite, and three with its Drill Claws.

Bite.Melee Weapon Attack: +17 to hit, reach 30 ft., one target. Hit: 36 (4d12 + 10). If the target is a creature, it is grappled (escape DC 20). Until this grapple ends, the target is restrained, and Metallor can’t bite another target.

Drill Claw.Melee Weapon Attack: +17 to hit, reach 35 ft., one target. Hit: 28 (4d8 + 10) slashing damage plus 20 (4d10) slashing damage if Metallor has activated Spiral Drive.

Ice Stinger Barrage (3/day). Metallor launches a volley of 2d6 explosive charges. The charges can travel 750 feet in a straight line and explode in a 50 foot radius. Creatures caught in the blast must make a DC 20 Dexterity saving throw or take 30 (6d10) ice damage and 30 (6d10) force damage, or half as much damage on a successful one.

Lightning Ripper (Recharge 5-6). Metallor fires a high-intensity blast of lightning energy from its mouth in a 250-foot cone. Each creature in that area must make a DC 20 Dexterity saving throw, taking 72 (18d8) lightning damage on a failed save, or half as much damage on a successful one.

Supernova Eruption (1/day). Metallor fires a high-intensity blast of incredible heat from its chest in a 500-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 100 (20d10) force damage and 100 (20d10) radiant damage on a failed save, or half as much damage on a successful one.

Legendary Actions

Metallor can take 3 Legendary Actions, choosing from the options below. Only one legendary action can be used at a time, and only at the end of another creature’s turn. Spent legendary actions are regained at the start of its turn.

Bite Attack. Metallor makes a bite attack.

Drill Claw Attack. Metallor makes a Drill Claw attack.

Heaven-Piercing Spiral Charge (Costs 2 Actions). Metallor merges its two arms into a single drill weapon and flies forward 400 feet in a straight line, striking any creatures in its path. Any creature that occupies a space through which Metallor charges is subject to a Drill Claw attack regardless of its size.

Homebrewery link

PDF link

Questions? Comments? Formatting or mechanics suggestions? Let me know! Just leave a comment or contact me. Stay tuned for more Dungeons & Dragons kaiju homebrew content. Next time, I’ll be coming at you with a more original creation, one not based on a Toho creation: Vermutila, the Queen of the Plague.

Thanks to /r/UnearthedArcana and /r/MonsterADay for formatting and mechanic suggestions.

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