ESOBIOLOGY

An alien ecosystem has crash-landed in the Overworld.

Thirteen species escaped the wrecks. Now they hunt, breed and spread on their own, whether you're watching or not. Find the fallen pods and arks, tranquilize the specimens and contain them in bio-vaults before they overrun your world.

Esobiology isn't a pack of static mobs standing in a field. Every creature runs a real routine: it wakes and sleeps, gets hungry, hunts, herds, courts a mate, raises young, defends its territory and drifts across the map as its population grows. Leave the ecosystem alone and it will change your world. Your job is to study it, tame it and decide what survives.

🌍 The core loop

1. Find the wrecks. Aliens don't spawn in the wild, they come from crash sites scattered across the world:

Pods — half-buried escape capsules with a single compartment. Each one releases a breeding pair suited to the local biome.
Arks — the broken mothership, torn into sections along a trail of debris and blown-open containment cells. An Ark releases multiple species at once and is far more dangerous to the balance of the Overworld.

Every wreck is generated procedurally, so no two look alike: oxidation, hull breaches and scarring change from site to site. Locations are deterministic and stable between sessions and each structure is built smoothly as you approach.

2. Track them down. Craft a Bio-Tracker to run a long-range scan that points you toward the nearest Pod or Ark, with direction and distance and tells you whether a site has already surfaced.

3. Sedate, then capture. Craft Tranquilizer Arrows and hit your target with them and an arrow together. A sedated specimen drops for about 20 seconds, enough time to close in. Sneak and right-click it with the right Bio-Container:

🟤 Copper Bio-Container — small, harmless species
⚪ Iron Bio-Container — mid-sized fauna
💎 Diamond Bio-Container — the big, dangerous ones

Bring too small a container, or approach standing instead of sneaking, and the creature wakes up: the peaceful ones bolt, the aggressive ones turn on you.

4. Release and build. Right-click a block with a full container to let the specimen out wherever you like: start your own alien preserve, stock a wildlife park or simply relocate an outbreak away from your base. Or don't release it at all and keep the population under control.

🧬 The species

Gentle giants & grazers

Titan Grazer — colossal, peaceful megafauna that browses on whole trees for food, sleeps at night and moves in herds. It won't hurt you, if you don't attack them, but it's enormous, so it takes a diamond container to catch.
Glimmerbuck — a softly duck-like herbivore. Travels in herds, breeds readily and sits near the bottom of the food chain: almost everything with teeth wants to eat it.

The sapient tribe

Hexasapiens — we found an intelligent species, the Hexasapiens. They use weapons and gear from mob drops and looted chests. They raise mud huts, claim beds, light a communal bonfire and have a social life. Hit one, crack open their chest or break a home and the whole settlement erupts in collective against you.

Predators

Stalker — an egg-laying nocturnal ground hunter of cold biomes. More hungry they are, more easily they will attack you. During the day, you can find them resting under trees, but during night be carefull.
Sarucopter — a nocturnal fly predator. By day it roosts in the treetops and sleeps; by night it climbs high and dive-bombs its prey out of the dark. Wake it and it will chase you down.
Lubnunenses — social pack predators that live a double life. By day they groom, nap and hunt small mob together. By night they follow you through the dark, where only their glowing eyes show and if you look right at them, they freeze in place. Look away and they creep closer. They'll also snuff out any torches and lanterns you've placed.
Gigapterion — the apex predator. A massive beaked terror that pursues relentlessly, chews straight through obstacles to reach its prey, naps once a day, and fiercely guards its nest until the egg hatches.

Ambushers, burrowers & small fauna

Sauvagesis — an alien funnel-web spider that digs a web-filled pit beneath itself and drags caught prey underground. If it catch you, you are dead. Be really carefull where you step your feet.
Molesect — half mole, half insect. It infests dirt and sand, hiding just under the surface, until a Scavenger sniffs it out and hauls it into the open or a prey pass above it.
Scavenger — a digger herbivore that forages and raids your crops, using its face tentacles to search in the ground for food.
Genicopter — a dragonfly-winged wader that hunts by standing still in the shallows and fishing and takes short startled flights when threatened.
Fracteria — a little pond amphibian that hops on land and skates across the surface of the water, snapping up fish.
Zen — a small, skittish biped that changes its markings to match its biome and flees the moment you get close. It lays clutches of eggs and breeds quickly, so keep an eye on its numbers.

🔥 Living systems

Predator hunger. Stalkers and Sarucopters carry a hunger meter from 9 (full) down to 0 (starving). The hungrier they get, the wider their prey list opens up — from passive animals only, to neutral and hostile mobs and the player, and finally to even the great Titans and their rival apex hunters. Self-defense always overrides hunger: strike one and it fights back no matter how full it is.
Day & night routines. Roosting, sleeping, herding, glowing eyes in the dark, torch-smashing night stalks, dawn dances. Behavior shifts with the clock and the weather.
Autonomous breeding & spread. Adults court, mate and raise young without any input from you, each species on its own timer. Populations grow and migrate, so an untended ecosystem expands.
Biome-aware crash sites. Which species a Pod or Ark releases depends on the surrounding environment, so different regions can grow different alien fauna and let the less adaptable die.

🍖 Extras

Raw & Cooked Exosteak — alien meat that drops from certain creatures; cook it in a furnace for a hearty meal. Or try to barter them with the Hexasapiens!
Full crafting recipes for the Bio-Tracker all three Bio-Containers and Tranquilizer Arrows.

📦 Installation & notes

Requires Minecraft Bedrock 1.21 or newer.
Apply both packs (Behavior + Resource) to your world; if the game prompts you to enable the pack's experiments, turn them on.
Works in survival, single-player and multiplayer.
Join our Discord to report bug or suggest new species: https://discord.gg/VDm3pXwpPR

Esobiology Release 1.0 — an alien ecosystem you can hunt, tame, and contain. The Overworld isn't yours alone anymore.