Serfs act as the working hooves for the buildings built on Anchorages. They are not well-suited to combat, but are an excellent workforce. A group of Serfs is called a swarm or a strike.

Serfs are quite small among subpuppets, standing at just 1' 4" (41cm) with slimmer builds. Their defining traits are their five legs, their fly-like insectoid wings, and their single bladed limb in place of what could have once been a sixth leg. Despite superficially resembling Imps, Serfs are not built for combat of any sort, with their bodies being much lighter and simpler. Their blades, while extremely sharp, are best suited for cutting and shaping Haetin. With their tiny builds and nimble five-legged bodies, they are extremely good at their job: Navigating between and inside buildings placed on Anchorages.

Serfs are almost entirely relegated to non-combat roles, but that doesn't mean they don't have a role in combat. They fulfill the roles of supply troops, both crafting new weapons and ammunition and dispersing it as needed. Serfs prioritize the operation and maintenance of Anchorage-operated structures in combat, be it supplying available Haetin to Emplacements and Federations, or fabricating and supplying ammunition to Sovereignties as they need it.

Serfs will even occasionally airlift an injured puppet to the rear battle lines, if the puppet is light enough to be safely carried. If the army is in desperate need of extra hooves on the front lines, Serfs can use their fine-bladed limb as a combat knife, which is more than capable of cutting through hide, skin, and even some lesser-reinforced metal armors like thin chainmail.

Serfs are generally just as busy outside of combat as they are inside it, constantly buzzing around an Anchorage's buildings (or multiple Anchorages' buildings if a city is formed) to gather materials, craft new items, and store them comfortably. If a Serf needs to rest and its host Anchorage does not have any available housing, it will roost against the underside of one of its Antlers. A single Serf is always spawned as a "twin" with its host Anchorage, making them the only subpuppet to be spawned from Hyacinth directly.

Serfs have an interesting epigenetic profile not due to what they have, but what they don't. There are a number of genomic sequences active in every other puppet and subpuppet type that aren't active in Serfs. This is believed to relate to their frailty and lack of combat ability, but there is no way to know for absolute certain. In terms of what they do share with other puppets, Imps and Arrays both have passing epigenetic similarities.

Serfs are capable of a wide variety of crafting skills, including pseudo-metallurgy using Haetin, smithing, construction, and even some amount of magical handiwork. While Manipulators are capable of their own brute work via knapping, woodwork, or other methods, Serfs are masters within the realm of Haetinworking, but struggle to incorporate outside materials in their tools.

The manipulation of Haetin is a Serf's bread and butter; the material takes various forms depending on how it is treated, and Serfs specialize in bringing out all of Haetin's potential. Several forms of Haetin are known to exist, and are each given names based on their properties:

• Raw Haetin: Raw, unprocessed Haetin, either created by mixing Anchorage blood with Serf saliva or produced directly in a pre-mixed form by Phylacteries. While all bases of haetin are viable, that which is produced by a Phylactery seems to be of a higher quality than the material mixed by-mouth, as Serfs will only feed Emplacements and Federations Haetin from a Phylactery (saving inferior-quality materials for civilian structures or repairs). While it isn't particularly useful or specialized as a material, Emplacements and Federations can utilize it directly in regular operation, and it is the base form from which all other types of Haetin come from.
• Haetin Shell: An airy, rough-textured material and one of Haetin's two solid forms. Haetin Shell forms a vast majority of Anchorage structures, giving the structures a beehive-like quality. While it is not as structurally strong or as durable as Haetanium, Serfs can form raw Haetin into Haetin Shell without any external tools. The material is also porous, which is assumed to facilitate certain operations within Anchorage buildings.
• Haetanium: Haetanium, also known as "Haetin Steel", is a heavily refined version of solid Haetin. Haetanium is the preferred choice for military applications; most tools and weapons, as well as ammunition casings for Sovereignties, are made from this highly refined material. Haetanium is only producible via a Foundry or the internals of a Federation; Serfs cannot make it on their own. It is assumed this limitation is why Haetin Shell exists, and why Haetanium isn't always used. The material boasts incredible properties across the board, sporting superior durability, resilience, and thermal dissipation to most forms of steel.
• Haetin Elastic: A semifluid permutation of Haetin used in places where string or elastic is needed. The elasticity of the material is seemingly freely adjustable, and as such, Haetin Elastic is more of a "class" of Haetin forms rather than one singular material. Whether it's found in bows, the internals of Analogues, or as emergency bindings for punctured Anchorage structures, it is a versatile material that seemingly doesn't require heavy Anchorage facilitation like Haetanium does.
• Haetin Flux: A soft solid form of Haetin with a consistency and texture similar to that of room temperature butter. It is made exclusively in Foundries or the insides of Federations, and despite its soft and unassuming texture, is actually a moderate-yield explosive used in Analogue ammunition.
• Haetin Mana: A gaseous form of Haetin produced only in Foundries. Haetin Mana is an extremely concentrated material, made vaporous by the intense concentration of magical energy running through it. Haetin Mana is only incredibly rarely seen outside of a Foundry; its energies are used in enchanting magical equipment made by Serfs, and have very little practical purpose.

Oh, the little Serfs... They may be small, but they're quite quick, and always full of surprises. Even I don't fully understand what goes on when they duck inside an Anchorage structure; though I've never minded. I know their parents will ensure they're well taken care of, and that they'll well take care of their parents in return. They might just beat out the Imps in sociality, and Manipulators in work ethic!

Sometimes I worry there's rivalry between my Serfs and my Manipulators, as they're all so excitable when it comes to making tools... Then I see the Manipulators gleefully tinkering with something the Serfs have made, and I realize that they work together just as much as they do apart.

Serfs were built into the design of Anchorages perhaps more tightly than any other subpuppet. While Reconcilants had Imps to start and Howitzers got Heralds as extensions of their role as artillery and spotter, Serfs and Anchorages are effectively inseparable; they break down fundamentally without one another. Anchorages need Serfs to work on them, and Serfs need Anchorages to work on. This tight bond ensures they have a distinct niche and modus operandi, even in a system where subpuppets (even those in significant number) are very common.