Size & threat
Subnautica 2 creatures — threat tier comparison
Subnautica 2's Early Access build has roughly 70 scannable fauna and leviathan-class entries in the codex. Unknown Worlds has not published canonical meter sizes for any of them, so this page groups by in-game danger rating (0–5) as the most reliable comparative axis. For leviathans specifically, including the World Tree, see the leviathans size chart.
About this page: Without official measurements, "size comparison" in Subnautica 2 is functionally a threat / role comparison. As Unknown Worlds adds PDA databank sizing during EA, this page will be updated.
Tier 5 — Leviathan / kill-on-sight (4)
Apex predators. Fleeing is the only option.
Tier 4 — Major hostile (2)
Sub-leviathan threats that can still wreck a Tadpole.
Tier 3 — Aggressive medium (7)
Bite + chase. Manageable in groups, dangerous solo.
Tier 2 — Light hostile / ambush (5)
Surprise damage, status effects, electric shock.
Tier 1 — Nuisance / harmless leviathan (4)
Passive 'leviathan-class' or small biters.
Tier 0 — Passive / ambient (48)
Safe to scan. Some are edible, decorative, or part of the ecosystem.
How to read this
- Tier 5 (leviathans): All five confirmed EA leviathans plus the Titan-class World Tree. See leviathans sized for visual scale.
- Tier 4: Major non-leviathan threats — Marrowbreach, Cerathecan. Will damage you and your Tadpole. Avoid unless you're prepared.
- Tier 3: Aggressive mid-size — Hammerhead, Bullethead, Sandspear, Tongue Thief, Twin Sitaray. Manage with knife + repair tool; avoid in groups.
- Tier 2: Lighter hostiles — Foureye, Waxmoon, Houndgar, Electric Geordie. Status effects (electric shock) are the main risk.
- Tier 1: Passive leviathans (Deepwing Brooder) and minor pests — safe approach but worth scanning.
- Tier 0: Ambient and passive — most of the ecosystem. Scan-fodder. Many are food / decoration / structural fauna (Awnworm, Stilt Orb, Coral Crab).
Notes on the data
- Danger ratings come from the wiki's structured entity data, which reflects in-game behavior at launch. They will shift as Unknown Worlds tunes creature AI during EA.
- Some bundle entries (e.g., "Aggressive predators", "Raions", "Pylons") group multiple species — see the individual codex pages for breakdown.
- The Bloom group (Bloom Parasite, Bloom Canker) is tracked separately from natural fauna because it's tied to the Bloom infection.
Related
- Leviathans size comparison
- Full codex
- Biomes — where each creature lives
- Beginner guide — what to fight, what to flee
Last updated: 2026-05-25. Threat tiers reflect EA launch state and are subject to balancing patches.