Ironback
Beast -- Medium -- Ruin debris margins, dense undergrowth, cache-rich soil systems, old foundation networks
It had dug through three layers of packed fill to get to the grain cache. Not around -- through. The fill was compacted rubble and old substrate aggregate that the settlement had been using as a floor for twenty years. It went through it like it wasn't there. Yolen said the claws are the part that surprises people, which is fair because the animal does not look like it has those claws. It looks like something built low and dense for no particular reason. The reason is underground.
-- settlement maintenance log, subfloor cache audit
Ecology
The Ironback is a compact, dense-bodied omnivore with a digging capability that exceeds anything of its size in the interior fauna record. The body plan is not optimized for speed or reach; it is optimized for ground contact and sustained mechanical force -- the wide stance, low center of gravity, and thick neck all support the forelimb-driven digging motion that is the animal's primary tool for both food acquisition and den construction. It can displace compacted substrate, old construction aggregate, and soft stone. The Burrow speed of 10 feet per round through soil and soft rubble reflects a capability that is slow by combat standards but represents a genuine environmental penetration ability that most animals and most parties lack.
The aggression profile is specific: Ironbacks are not predatory toward large creatures under normal conditions, but they defend their den sites and their immediate space with remarkable commitment for their size. The Multiattack -- Bite and Claws -- is available to an animal that AC 12 and 26 HP; at CR 1/4 it is capable of putting real damage on a character who disturbs a den. The more common encounter is the animal defending a food cache from a party that did not realize a food cache was present, or a party attempting to clear a den site the Ironback considers non-negotiable.
They are solitary except during mating season, with den territories that extend over significant underground area. A ruin complex with a mature Ironback in residence will have an extensive tunnel network through the substrate layers -- not a hazard in itself, but a structural consideration for any settlement or group that needs to use the floor above as a load-bearing surface.
In high-Miasm zones, the keratin layer of the claws develops the same mineral-compound incorporation that the Siltjaw and Tidecrab show in saturated aquatic environments: denser, harder claw material with a faint grey-green sheen that gives the animal its name in communities that have seen enough of them to have named anything. The practical effect is a marginal increase in the digging capability that the animal already has. Researchers who have studied the claw material report that the nanite-mineral compound has properties similar to low-grade alloyed metal in both hardness and conductivity.
Stat block
| AC | HP | Speed | Initiative |
|---|---|---|---|
| 12 | 26 (4d8 + 8) | 30 ft., Burrow 10 ft. | +1 (11) |
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 15 (+2) | 10 (+0) | 15 (+2) | 2 (-4) | 12 (+1) | 5 (-3) |
Senses Darkvision 30 ft.; Passive Perception 11
Languages None
CR 1/4 (XP 50; PB +2)
The Ironback makes one Bite attack and one Claws attack. Melee Attack Roll: +4, reach 5 ft. Hit: 6 (1d8 + 2) Piercing damage. Melee Attack Roll: +4, reach 5 ft. Hit: 5 (1d6 + 2) Slashing damage.Multiattack
Bite
Claws
Encounter use
The Ironback encounter is most effective as a site problem rather than a tactical fight. A den is occupied; the party needs that space. The Ironback defending the den has Multiattack at CR 1/4, which means it will injure someone before it goes down, and the tunnel network it has been building is now a structural issue for whatever happens in this location after. Use the Burrow speed to have the animal disappear into the substrate mid-fight and reappear from an unexpected direction -- not because it is tactical, but because that is what a burrowing animal does when cornered. An Ironback that reaches a tunnel it knows goes somewhere the party cannot follow has functionally won the encounter even if the party considers it a retreat. The claws-through-substrate capability is also useful as an environmental note: a party trying to break through a floor to reach a lower level finds the task already partially done by an Ironback that was working the same project from the other side.
Salvage
The claw material in high-Miasm specimens is the primary research interest: the nanite-mineral alloy that forms in the keratin layer has been studied for applications in both cutting tool manufacture and in Lattice-connected sensor systems where the conductivity of the compound is relevant. Standard-zone claws are used as digging and scraping tools in construction and excavation, where the grip and curvature prove practically useful. The fat layer in the CON-heavy body plan renders into a useful compound for waterproofing and joint lubrication. In communities that regularly encounter Ironbacks, the tunnels they leave behind are treated as found infrastructure -- mapped, reinforced where useful, and closed where they compromise structural integrity. The animal built something that persists after it is gone.