Leviathan-class organisms

Any organism exceeding a certain size threshold is classified as "leviathan-class" by the PDA in the Subnautica franchise. These creatures range from passive filter-feeders to the most dangerous predators on their respective planets.

Subnautica 2 leviathans

Collector Leviathan

The first hostile leviathan revealed for Subnautica 2. See the full Collector Leviathan article. A squid-like predator with four main tentacles, mandible feeding tentacles, roar/shockwave attacks, and AI-driven behavior that reacts to player actions in real time. Found in the Sparse Plains biome. Cannot be killed.

One additional leviathan was cut from the Early Access scope. Its identity has not been revealed.

Original Subnautica leviathans

Reaper Leviathan

The most iconic hostile creature in the franchise. Approximately 55 meters long, roughly the same length as the Cyclops submarine. Highly aggressive, using four mandibles to grab vehicles and players. Found in the Dunes (8 individuals), Mountains (7), and Crash Zone around the Aurora (11). Deals 80 damage per bite. The creature that most Subnautica players remember from their first traumatic encounter.

Ghost Leviathan

Translucent, bioluminescent predator. Juveniles measure approximately 67 meters; adults reach approximately 107 meters. Three adults patrol the map: two in the Grand Reef and one in the Northern Blood Kelp Zone. Three juveniles inhabit the Lost River. Additional Ghost Leviathans spawn progressively in the Crater Edge (Dead Zone) if the player ventures beyond the map boundary.

Sea Dragon Leviathan

The largest hostile creature in the original Subnautica at approximately 112 meters. Found in the Inactive Lava Zone (2) and Lava Lakes (1). Attacks include arm swats, molten rock projectiles, fireball barrages, and swallowing the player whole. Capable of exerting over 300 tons of force when ramming.

Sea Emperor Leviathan

The largest living creature at approximately 200 meters. Non-aggressive, sapient, and telepathic. The only one in the game, imprisoned in the Primary Containment Facility. Voiced by Lani Minella. See the full Sea Emperor Leviathan article.

Reefback Leviathan

Passive leviathan approximately 70 meters long. Carries entire mini-ecosystems on its back. Flora, coral, and small fauna grow on its massive carapace. Produces a distinctive moaning sound. Found floating through Grassy Plateaus, Mushroom Forests, and other mid-depth biomes.

Sea Treader Leviathan

The smallest leviathan at approximately 20 meters. Passive unless provoked. Unique because it walks along the seabed on long, double-jointed legs rather than swimming. As it walks, it unearths Shale Outcrops containing diamonds and gold. Found on the Sea Treader's Path.

Below Zero leviathans

Chelicerate

Aggressive predator approximately 40 meters long. Found in Purple Vents and Tree Spires. A larger variant, the Void Chelicerate (approximately 65 meters), patrols the World Edge.

Shadow Leviathan

Approximately 60 meters. Extremely aggressive, with a mouth on the underside of its body. Found in the Crystal Caves and Fabricator Caverns.

Ice Worm

Approximately 95 meters. A land-based leviathan confined to the Arctic Spires. Burrows through ice and attacks from below. Can be repelled with Thumper devices.

Ventgarden

The largest Below Zero leviathan at approximately 110 meters tall. Completely passive. Part jellyfish, part living garden. Takes in nutrients from thermal vents and hosts an internal ecosystem that the player can swim inside to explore.

Glow Whale

Passive creature covered in bioluminescent photophores. Gentle giants that harbor barnacles and algae on their bodies.

No-weapons philosophy

In Subnautica 2, leviathans cannot be killed. Design Lead Anthony Gallegos described lethal solutions as "boring" and confirmed the game has "no weapons, only collection tools." In the original Subnautica, players could technically kill leviathans with the survival knife or gas torpedoes, but it took extended effort and was never intended as the primary interaction. Subnautica 2 removes this option entirely.