Spawn animals and build a population

Create mammals with Npc.create, using an animal soul from Npc.animals(). They use the same server-owned orders and events as human NPCs.

const sheep = Npc.create({
  soul: "animal_sheep_ewe",
  position: player.position,
  virtualWorld: player.virtualWorld,
  nametag: false,
  interactable: false,
});
console.log(`${sheep.id}: ${sheep.soul}`);

Place animals on walkable ground with enough space for their bodies. For automated placement, use the server’s navigation mesh and handle a null result from Navigation.closestPoint or randomPoint.

Choose an animal

const wolves = Npc.animals().filter(row => row.actorClass === "Wolf");
console.log(wolves.map(row => `${row.name}: ${row.soul}`).join("\n"));

Each catalog row contains name, soul and actorClass. Passing the name or soul GUID selects the matching native class. A conflicting explicit class is refused. Human outfits, worn items and appearance overrides are also refused for animals.

The catalog covers sheep, cattle, pigs, boar, hares, red deer, roe deer, wolves and wild dogs, including quest variants. Prefer generic animal_* entries for ordinary populations. Horses use Horse.spawn, and companion dogs use Dog.

Populate the world deliberately

The game’s default mammal, horse and dog spawning is suppressed. Native chicken flocks are suppressed too; there is no chicken spawning API. Other ambient wildlife is unaffected. Your server must create the animals it wants through Npc, Horse and Dog.

Npc.animalSpawnpoints() returns the running level’s authored spawn markers. Pass a level name, or "*" for all catalogued levels:

const sites = Npc.animalSpawnpoints();
for (const site of sites.slice(0, 5)) {
  console.log(`${site.guid}: ${site.name}, ${site.actorClass}, count ${site.count}`);
}

Field	Use
guid, level, name, layer	Identify and select a placement. Keep GUIDs as strings.
soul, actorClass, position	Choose the animal and locate its authored marker.
count, respawnDays, spawnInFlock	Read the original game’s configuration. These do not create multiplayer rules.
spawnAreaGuid	Find the linked area, when one is recorded.

Markers may belong to quest layers and may sit above the ground. Their presence in the catalog does not mean they are active or safe spawn points. Project them onto the mesh before creating a body. Set your own population cap and choose which sites to enable.

Roaming and fighting

Animals accept moveTo, patrol, follow, flee and hold through Npc. They avoid doorways. Narrow passages may still block a body, so handle failed orders and retry after a delay rather than every frame.

const destination = Navigation.randomPoint(npc.position, 12, { doors: "none" });
if (destination) npc.moveTo(destination, { speed: "walk", pathfinding: "server" });

Wolves and wild dogs can use attack(target) for ordinary bites. Other animals cannot attack, and animals cannot use bows. Choosing prey, protecting teams and limiting pursuit are game-mode decisions. Named World Builder patrols also work for animal NPCs; validate with { actor: animal } to use their door policy.

Try the default population manager

The default game mode provides /animals list, /animals start <spawnpointGuid> and /animals stop. It enables all populated sites on the current level in world 0 once Navigation.ready is true. In src/server/animals.ts, animalSpawnpoints: null selects those sites, a GUID list selects specific sites, and [] disables startup sites. A command-started site uses the caller’s virtual world. /animals list lists sites; it does not create a population by itself.

The sample allows up to four slots per site and 256 animal bodies across all sites, including corpses. Sites wait when that cap is reached. Animals roam within 20 metres of home; predators acquire players within 18 metres and stop pursuing outside a 45-metre home leash.

After death, replacement waits five to six real minutes and for the corpse to be removed. Corpses remain for at least 90 seconds, and are removed only with players at least 60 metres away. Spawns need a ready player within 350 metres and no visible player within 60 metres of the marker or spawn point. This is a distance test, not a line-of-sight test. Living animals are removed when players leave the activation area and are far enough from the body, freeing capacity for other sites. Navigation work and spawning are spread across server ticks.

The sample prepares animal loot at spawn. Its meat and special-part chances are game-mode settings; Corpse loot explains the stock and harvest APIs.

These limits and timers belong to the sample. They do not use the catalog’s respawnDays or persist across resource/server restarts. A custom population manager should own its timers and NPC IDs, remove only its own animals on shutdown, and save any state it needs across restarts.