Ant, Iron

Medium swarm of Tiny elementals, unaligned

Armor Class 18 (natural armor)
Hit Points 39 (6d8 +12)
Speed 20 ft., climb 15 ft.

12 (+1) 13 (+1) 14 (+2) 1 (-5) 8 (-1) 1 (-5)

Damage Vulnerabilities lightning
Damage Resistances piercing, slashing
Damage Immunities bludgeoning
Condition Immunities charmed, frightened, paralyzed, petrified, prone, restrained, stunned
Senses blindsight 15 ft., passive Perception 9
Challenge 2 (450 XP)


  • Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Tiny insect. The swarm can’t regain hit points or gain temporary hit points.


  • Bites (Swarm). Melee Weapon Attack: +9 to hit, reach 0 ft., one creature in the swarm’s space. Hit: 8 (2d6+1) piercing damage, or 4 (1d6+1) piercing damage if the swarm has half its hit points or fewer.
  • Bite (Individual Ant). Melee Weapon Attack: +4 to hit, reach 0 ft., one target being crawled upon. Hit: 1 piercing damage.


Initial Round-A swarm of iron ants will go after whatever person or creature bearing the most iron, copper, or other objects made from natural metals. It is their instinct to seek out concentrations of their primary diet.

Subsequent Rounds-A swarm of iron ants that finds itself attacking a target that has been knocked prone, paralyzed, and/or unconscious will crawl all over the target-but only to seek out juicy metal bits to tear off and take away to feed the swarm. The ants are looking for a meal; they don’t bear vengeance or ill will, and they do not fathom their advantage in any tactical sense at all.

Defensive Round-Destroying the swarm is as much dispersing it as it is killing the individual creatures. Considering how sturdy individual iron ants are, when the swarm reaches 0 HP it is effectively destroyed, but 2d10 individual ants scatter from the last space the swarm was in – and can be caught using DC 12 Dexterity saving throw.


The sound of a thousand needle-pointed legs scurrying across the cobblestone floor, the occasional clink of ferrous exoskeletons mingled throughout, announces a carpet of inch-long elemental vermin-the iron ants.

Serving as carrion scavengers on the elemental plane of earth, iron ants are almost omnipresent there, scurrying about to find and claim bits and flecks of raw metal throughout the landscape and returning with them to their central nest and their enormous, hidden queen.

Individually the iron ants are roughly one inch long, bearing the same body structure as a large, steel-grey carpenter ant with a body comprised entirely of solid cold iron. If it weren’t for their constant scurrying and wriggling, an onlooker might think of an iron ant as some kind of forge-born sculpture.

Iron ants are commonplace vermin on the elemental plane of their origin. They are often tucked away in the cracks of a proper elemental, or stashed in the folds of a dao’s flowing robes. However, they might be hidden, when those beings are called to the prime plane for whatever reason, or when travelers carelessly dimension door their way through, the occasional iron ant might accidentally come along for the ride and end up stranded on the prime plane. When that happens, the straggler ants instinctively begin to seek out each other to form swarms to better their chances of survival.

On their home plane, iron ants roam about finding ore scraps and other metallic leftovers to dine upon and bring back to their queen. on the Prime Plane their instincts have not changed, but their menu has. Raw ore is not as easy to come by as it is on their home plane, so these roving swarms are drawn to collections of smelted materials, worked metals, and if they must – alloys. The ants do not individually eat much, leaving behind tiny scratches on metallic objects, taking weeks to scrape a dagger or ingot to bits as they carry it around within the swarm, searching for a way to their impossibly distant nest queen.

d6 Iron Ant Treasures
1 1d4 gp worth of natural iron/copper ore.
2 2d8 copper pieces; 50% chance for a slightly chewed upon dagger.
3 A random metal martial weapon, only slightly chewed upon.
4 A suit of half-plate with the buckles chewed off, requiring 2d10 gp worth of repairs.
5 3d20 silver pieces in a hollow monster skull.
6 A buckler shield made from either mithril or adamant (50% chance of either).
Section 15: Copyright Notice

Book of Monstrous Might (C) 2021 Total Party Kill Games. Author(s): Brian Berg, Mark A. Hart & Danny Grimes.

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