Creature Compendium
Threat levels, drop tables, biome locations, and survival strategies for every notable creature in Subnautica 2.
The Ecosystem of an Alien Ocean
Subnautica 2 places you inside a living underwater ecosystem — one that does not revolve around you. Creatures feed, migrate, hunt, and nest regardless of your presence. The ocean was there long before your lifepod hit the water, and it will carry on whether you survive or not.
This is worth remembering when planning encounters. Unlike most survival games, Subnautica 2 does not expect you to fight. Combat is possible but rarely optimal. The Bioscanner, careful positioning, and awareness of creature behavior patterns will keep you alive more reliably than any weapon. Leviathan-class creatures in particular should never be engaged directly — they exist to be avoided or carefully navigated around.
Many creatures are also resource sources. The Necrolei drops Necrolei Cysts used in crafting Strong Acid. Armored fauna drop Creature Enamel for Enameled Glass. Understanding which creatures provide what — and how to harvest safely — is a major part of mid-to-lategame resource progression.
Creature behavior also varies significantly by depth. The Safe Shallows fauna are almost entirely passive or easily avoided. Past 200m, the calculus changes. Past 400m, you are in leviathan territory, and the rules are different entirely.
Threat Level Key
Will not attack under any normal circumstance. Safe to approach closely.
Ignores you until provoked or accidentally triggered. Maintain distance.
Will detect and pursue you within a territory radius. Stay aware of positioning.
Top-of-chain predators. Capable of destroying vehicles. Avoid entirely unless prepared.
⚠ The Necrolei — High Priority Target
The Necrolei is one of the most searched creatures in Subnautica 2 because it drops Necrolei Cysts — a rare organic material needed to craft Strong Acid, which in turn is required for several advanced recipes. The creature is aggressive, territorial, and found at significant depth (250–600m), meaning you need a properly upgraded suit and good situational awareness before attempting a harvest run.
Key approach: use the Bioscanner to identify cyst node locations on the creature before getting close. Approach from the side or below — the Necrolei's lunge is forward-facing. After harvest, back away immediately; the creature re-aggros fast. Bring a Repulsion Cannon as a panic tool.
Necrolei
A deep-sea ambush predator with bioluminescent lure appendages and an armored exoskeleton. Produces toxic cysts as a defense mechanism.
Don't approach head-on — the Necrolei lunges when its lure is disturbed. Approach from below and use the Bioscanner to identify cyst nodes. Collect cysts by getting close to the side, not the front.
Tadpole
Small, harmless filter-feeding creatures that gather in large schools. Found near bio-luminescent structures called Tadpole Pens.
Tadpoles themselves aren't harvestable, but the Tadpole Pens they inhabit contain valuable upgrades and locked containers. Use the Sonic Resonator with the correct keycode to access pens.
Angel Comb
A large, ethereal filter-feeding jellyfish-like creature with spectacular comb-row bioluminescence. Harmless unless provoked.
The Angel Comb is non-aggressive but its trailing tentacles deal contact damage. Give it a wide berth when passing underneath. Stunning it briefly with the Sonic Resonator allows safe passage.
Collector Leviathan
A massive territorial leviathan that 'collects' objects — including vehicles — and stores them in vast debris fields near its lair. One of the game's most dangerous creatures.
Do not engage. The Collector Leviathan will grab your Seamoth and drag it to its cache. If you find collected debris with rare blueprints, wait for the Leviathan to patrol away before looting. Use a Cyclops with Silent Running to traverse its territory.
Dealing with Leviathan-Class Creatures
Leviathans have enormous health pools and deal vehicle-destroying damage. There is no early-game weapon that makes this a viable fight. Avoidance is always the correct play.
If you have a Cyclops, enabling Silent Running dramatically reduces detection range. Slow down to minimum speed and give leviathans wide berths when passing through their territory.
Leviathans follow patrol patterns. Spend a minute observing from a safe distance before crossing their territory. They have predictable loops — use that predictability.