Follow TV Tropes


Characters / Subnautica

Go To

    open/close all folders 

Aurora survivors

    Ryley Robinson
The sole survivor of the Aurora. You are stranded on an alien planet and you have to find a way to adapt and survive.
  • Action Survivor: As a person who appears to be a lowly systems maintenance guy for an interstellar company, he probably spent his previous days sitting inside a spaceship and keeping its systems online. After the crash, he not only manages to outlast any of the other survivors but saves a world he never knew and manages to get off of it.
  • Alliterative Name: Ryley Robinson.
  • Ambiguously Brown: Of the "future people are all one race" style.
  • Anime Hair: One of the few things we know about the male protagonist is that he has a huge fauxhawk. Unknown Worlds staff have joked that the one concrete thing they know about his personality is that his favourite thing in the world is hair gel.
  • Almighty Janitor: Prior to the crash, Ryley was the "Non-Essential Systems Maintenance Chief", which sounds like a really fancy way of saying "Head Janitor".
  • Badass Normal: He's just a low-level ship maintenance worker thrown into a desperate fight for survival on an alien planet, but he quickly copes with the shock, sets himself up for the long haul and perseveres against all odds. When the credits roll, he has survived countless predator attacks, cured a terrible alien plague, saved an ancient species and, through them, the whole planet from extinction, and made his way back home.
  • Fluffy Tamer:
    • It's possible to tame Stalkers by feeding them prey, which can help gather resources. Be careful, though. They can still attack you.
    • Another, more permanent, method is to acquire an egg and hatch it in an Alien Containment. All fauna raised this way are permanently friendly towards you, even if released into the wild. Breeding Stalkers to help hunt down salvage (and farm their precious teeth) is but one application.
  • Heroic Mime: Doesn't utter a single word in the game. The only thing you'll ever hear from him are grunts of pain or gasps for air.
  • In-Series Nickname: The AI addresses them as Survivor, likely to avoid giving them a canon name. You are also called "Captain" when you enter a vessel or building. This either means you are the captain of whatever vessel or building you've created, but it could also mean that you've been designated the de-facto captain of the Aurora and its subsidiaries due to the fact that you're the only survivor.
  • Instant Expert: Although he's basically a janitor in all but name, Ryley can utilize any tech he interacts with pretty much instantly. That includes the Cyclops, a submarine with a standard crew complement of three that only trained experts are supposed to be able to handle solo.
    • Semi-justified: being a glorified janitor means practice using fabricators, repair tools and scanners, reading the instructions, interpreting and following the PDA, some possible fork-lift experience from negotiating with stores and other hands-on, general skills... Ryley's job would have given him some foundations he could build on to survive with, besides his incredible luck in not coming down, say, near a Crabsquid on day one. Unlike poor, out-of-his-depth Medical Officer Danby who perished near Lifepod 12 (probably via Warper rarther than illness).
  • Olympic Swimmer: While you have an Oxygen Meter (only 45 seconds with just your own lungs), you can swim for an infinite amount of time and suffer no fatigue.
  • Reduced to Ratburgers: You have to eat certain creatures and plants in order to survive on the planet. The AI notes that, while the idea of eating a dead animal may disgust you, humans have been doing it for thousands of years. Some of the fish do look pretty normal in terms of fish your average Westerner would consider food species, but others are decidedly alien. You also eat parts of the fish most people would pass over: Peeper eyeballs are apparently rich in protein. Handwaved by the fact the Fabricator is stated to remove internal organs and generally sterilize the fish in the process of cooking/curing them for consumption.
  • The Sleepless: You never need to sleep once in this game. Even though there's a day-and-night cycle you can fast-forward by sleeping in one of three bedding options you don't actually need sleep.
    • The Needless: In Freedom mode, you don't have to worry about hunger or thirst, either, though you still have to watch your health and oxygen. In Creative mode, you don't even need to watch those.
  • Sole Survivor: The only human of the Aurora. Subverted as you're not the only one to survive the explosion at first anyways. After the ship is shot down, many life pods managed to eject. However, as soon as they made planetfall, the other survivors got picked off one by one by radiation, the local wildlife, injuries caused by the crash, or they were straight up hunted down by the warpers who are designed to kill anything capable of screwing with the alien systems and can bring the Kharaa disease off the planet, as well as anyone who's been infected by the Kharaa. Your character is simply lucky enough to land in a safe zone which is why you are able to get a foothold on the planet and survive.
  • Swiss Army Weapon: You can craft a survival knife, which you can use to harvest Creepvine and other plants. You can also upgrade and make it more powerful to emit heat (which auto-cooks fish it's used to kill). Knife durability was removed for convenience late in Early Access, and now the knife is both (generally) your first proper tool and one which persists through the rest of the game.
  • Unfazed Everyman: Ryley doesn't show any reaction at all to the predicament he's in, nor to all the crazy stuff and fearsome creatures he encounters on the planet several times a day. If he does feel anything about it, he never bothers to tell us.
  • You Gotta Have Blue Hair: While most of it is black or dark brown, Ryley has several blue-green streaks in their hair. Given how a number of other characters share this trait, it appears to be part of the Alterra dressing code.

The artificial intelligence inhabiting your PDA and vehicles. Voices for the Aurora, your PDA, Seabases, the Seamoth and the Neptune escape rocket are female, though the Cyclops and the Prawn possess male voices.
  • Accent On The Wrong Syllable: The Prawn AI talks more or less normally, but the others have very peculiar accentuation.
  • Badass Baritone: The Cyclops AI has an impressively deep voice, but the badass effect is often diminished by it randomly shooting up to much higher pitches for a word or two.
  • Deadpan Snarker: Older versions had the PDA's first greeting to you be "Congratulations on not dying."
    Cyclops: Welcome aboard, Captain. Some systems need attention.
    • When you first build an observatory module, the PDA immediately remarks in the log about how they're "imprudent" (i.e "irrelevant") to survival.
    • When entering the Dunes or Mountains, the PDA takes note of the multiple Leviathan-class lifeforms and asks if you're "sure what you're looking for is worth it?"
    • The PDA also doesn't take your situation into consideration at times:
      PDA: Congratulations, survivor. You have exceeded your weekly exercise quotient by 500%. Data indicates that swimming was your favourite activity. Be sure to vary your routine for uniform muscle development.

      PDA: The Seamoth is a fast, safe mode of transport, but remember that swimming is good for your glutes and endorphin levels.
    • The first time you collect copper ore:
      PDA: Copper is an essential component of all powered equipment. Your probability of survival has just increased to: unlikely, but plausible.
    • The first time you build a nuclear reactor in your seabase:
      PDA: Exercise caution when handling radioactive materials. Exposure risks corrupting your PDA's recording of the circumstances of your death.
  • Expospeak: Upon first emerging from your lifepod, the PDA will provide details about the surrounding environment — including the patently obvious, such as being mostly covered in water.
    • Also designed in tandem with the scanner to assess local flora and fauna whilst assigning them "easy to remember names."
  • Nightmare Fuel Station Attendant: Upon venturing deeper into the ocean and encountering the "blood kelp" biome:
    PDA: This ecological biome matches 7 of the 9 preconditions for stimulating terror in humans.

     Aurora Crew 
The other members of Aurora's crew; twenty-three on the Command team, eighty-five engineers, forty support crew and nine civilian passengers, totalling at 157 people overall. All appear to be dead aside from one — the player character.
  • Apocalyptic Log: This is basically the only means of identifying the crew who made it to the planet, their PDA's being all that's left of them by the time the player awakens. One voice log in particular even voices this directly; upon one passenger's request to keep the decidedly-embarrassing details of their death note  a secret, the surviving crewmember remarks the secret is safe with him because he doesn't expect to make it off the planet, to begin with.
  • By-the-Book Cop: While not an actual cop, 2nd Officer Keen seems to come across as this, being the highest-ranking authority next to Captain Hollister and taking the regulations very seriously.
  • Cheaters Never Prosper: Medical Officer Danby cheated on his license exams and doesn't actually know anything about treating illnesses. Not like proper medical expertise would have helped him with his case of Kharaa, but it's the thought that counts.
  • Doomed Contrarian: Though Officer Keen and CTO Yu managed to escape their lifepods and reach the rendezvous on the floating island, Yu insisted that the pair immediately leave to board the Aurora and use the communications equipment to contact fellow survivors, and she doesn't take no for an answer. On the way there, they met a Reaper, with predictable results. Had they stayed on the island like Keen wanted, they would have found the Degasi habitats with their still-stocked growbeds and, later, been reunited with the player, which would have made their survival vastly more likely.
  • Face Death with Dignity: Jochi Khasar is last heard praying for his gods, saying that he is, "done playing as this bundle of flesh," as the systems in his lifepod shut down while it enters the atmosphere, ending his prayer by saying, "Return me."
  • The Faceless: Aside from a photograph of a female crewmember in some lockers, we never actually see any of the other crewmembers, alive or otherwise, as their bodies have either been eaten by the wildlife or been taken away by the Warpers for disposal of "infected individuals".
  • The Gadfly: CTO Yu seems to have had shades of this, having reprogrammed a remote drone to respond to certain ways of voicing orders just to inspire unusual reactions in others out of pure boredom.
  • Heroic Sacrifice: Captain Hollister refuses to abandon ship and guides the Aurora to a controlled crash, hoping that the ship will be left intact enough for the survivors to utilize.
  • Unwitting Instigator of Doom: Mongolian diplomat Jochi Khasar, by requesting Alterra's help with his search for the Degasi, is the whole reason the Aurora detoured to 4546B in the first place.

Other Survivors

    Degasi survivors 
Three people who initially survived the crash of the Mongolian ship Degasi and have left evidence of their presence on Planet 4546B. They include: Paul Torgal, the captain of the Degasi; Bart Torgal, his son, successor, and a bioengineer; and Marguerit Maida, a mercenary hired to protect the ship against pirate raids.
  • Action Girl: Uber-badass Marguerit Maida.
  • Action Survivor: Marguerit ensured the immediate survival of the group and Bart gave all he could to establish longterm conveniences.
  • Ambiguous Situation: While it is clear that the last Degasi base was destroyed by a leviathan, it's unknown whether it was a Reaper or a Sea Dragon. While the dialogue implies that a Reaper was the one to destroy the base, the roar the plays just prior to the attack is that of the Sea Dragon. Both fit Paul's description of an alien Kraken and would have valid reasons to attack the base - the Reaper to save its kin and the Sea Dragon to obtain an easy meal. That being said, most people assume it was the Reaper that did this.
  • Blood Knight: Marguerit keeps stabbing the fish Bart needs alive to research.
  • Defiant to the End: Margureit was last seen hundreds of meters below the surface, with limited oxygen supplies, no way to return to safety, going toe-to-tail with predatory Leviathan, armed only with a jagged piece of scrap metal and an underwater scooter.
    • Subverted. SHE LIVED.
  • Despair Event Horizon:
    • Paul and Bart both cross this after Marguerit's bringing a live-but-stunned Reaper to their base for study results in another of its kin attacking them.
    • Paul is left alone in the depths after Marguerit goes out in a blaze of glory against the Leviathan, his last log being to state he's low on oxygen and the scent of his blood is in the water with disquieting calm, having clearly accepted what seems to be his impending death.
    • Bart somehow manages to make it back up to the Floating Islands through unknown means. He reveals that he knew something on the planet didn't want them down that deep, but he didn't tell Paul or Marguerit about it and blames himself, implying he thinks whatever wanted them out had a hand in the Leviathan attack. He then laments that they shouldn't have left the island and that he deserves his loneliness, implying that he dies alone in what's left of their original bases.
  • River of Insanity: The Degasi got on it the moment Paul ordered a detour to check Planet 4546B for valuable resources. In his defence, he got them. Preposterously, they do it again. They left their island paradise so they could go get more minerals, and then Marguerit loses her mind and convinces them to go even deeper to a place with even more monsters.
  • Redemption Equals Death: Played with; while never explicitly stated, one could interpret Marguerit's final charge against the Reaper Leviathan in order to save Paul as this, possibly thinking in hindsight it was folly to bring it to their base.
    • Subverted in that she lived
  • Suddenly Always Knew That: Bart Torgal got an implant to know how to do biological engineering before the Degasi crashed. As the heir of a family of merchants, there wasn't any particular reason for him to purchase the implant, but it sure came in handy when he got stuck on Planet 4546B.
  • Jerkass: Paul. For someone stranded on an alien world, he doesn't seem to have gotten the memo that survival in a group requires everyone working as an equal; trying to pull rank when you don't have a ship gets you nothing but resentment. Granted, Maida doesn't fare much better; her resentment of "corporate types" in general leads her to mistrust and challenge Paul more than is necessary.
  • Jerkass Has a Point: Despite his bossiness and arrogance, Paul ironically remained the most cautious of the Degasi survivors all-throughout. In fact, in the second-to-last log where it turns out Maida was reckless enough to tow a living Reaper Leviathan to their base, Paul's calling Maida crazy — both for the risk of the Reaper and of drawing others down to try and save it — is quite justified.
  • Pride: The fatal flaw of both Paul and Marguerit — the former because of his status and having always lived being in charge of his surroundings, the latter because of her gung-ho attitude and presumption that her greater survival experience meant she knew better than everyone else. Paul's arrogance in going to an unknown planet in secret got them all stranded, while Marguerit's arrogance in taking a live Reaper back to their base ultimately got them all killed.
  • We ARE Struggling Together: Paul and not get along. Almost every single log you find from the group involves them fighting over something, with Bart stuck in the middle. Even in Paul's last log, where he notes Marguerit saved him from a leviathan it comes off more as she saved him by accident as she happened to be fighting it rather than deliberately wanting to help him.

    Craig McGill 
A man who survived 47 months stranded on an island alone before arranging his return to civilization.
  • Action Survivor: "[R]emember Craig McGill, who crash-landed in the acid swamps of Boreal 9 and fought off arachnid kidney-poachers for 47 months, before hijacking a tame starwhal and riding it to the nearest phasegate."
  • A Hero to His Hometown: The PDA gives you two log files relating to McGill's feats while stranded to remind you that you can survive too.
    • His exploits are also basis for a VR training simulation used by the company. Nobody ever managed to survive more than just handful of days.
  • Determinator: The reason why Alterra's AI likes to bring him up as an example for other survivors.
  • Reduced to Ratburgers: "Craig McGill survived 47 months on live tree-roaches and stankroot, prepared as a healthy, raw salad."
    Marguerit Maida 
A security guard on board the Degasi. Marguerit help the survivors on their initial crash, until she was lost at sea with limited oxygen. Below Zero reveals she survived, drifting into the artic atop the corpse of the Reaper Leviathan she had killed, burning its fat for warmth and to cook its flesh for survive. Marguerit seems to be the sole living human on the planet by the time Robin arrives.
  • Action Survivor: Survived the crash on the Degasi and her encounter with a Reaper. She floated on it's body for three weeks, eating its flesh and using it's chest-cavity for shelter and burning it's fat for warmth until she eventually washed up in Sector Zero.
  • Battle Trophy: she keeps the skull of the Reaper she killed in the first game as a trophy in her base.
  • Blood Knight: She encourages Sam Ayou to use terrorism to stop Alterra's research when it became clear that stopping them diplomatically wasn't going to work. Margeurit tells Sam to use bombs to blow up specific facilities, but decides that she wants to blow up Omega Lab instead because it'll be fun.
  • Contralto of Danger: She has a low, smoky voice.
  • Cool Old Lady: She's in her late fifties or early sixties by the time Robin meets her, and her hair is going gray. This hasn't stopped her from living off the land for the last ten years on 4546b and even recently bombed Omega Lab for fun.
  • Doesn't Trust Those Guys: Maida does not trust people who are too big to fight and too wealthy to be bought off. This is part of why she doesn't like Alterra, as they are both.
  • Dying Moment of Awesome: The last time Maida was seen was when she was stabbing a Reaper in the eye as it dragged her off to her death.
    • She survived and washed up in Sector Zero.
  • Establishing Character Moment: In Below Zero, Robin first meets Margeurit when she drops from the sky in a PRAWN suit covered in bone armor and wielding a bone sword, where she promptly reveals she's hostile to Alterra personell and demands that you "get off her land".
  • Going Native: She's basically made Sector Zero her home, and she's hostile to Alterra's presence in the area (and anyone she suspects of being Alterra), and doesn't seem like she intends to leave. She demands that Robin "get off her land" when they first meet.
  • Improvised Weapon: She uses a piece of scrap metal to gouge out the eye of the Reaper who attacked the third Degasi seabase.
    • Bad with the Bone: In Below Zero, her PRAWN Suit has a Chelicerate mandible as an improvised sword. The PDA notes that she should have access to more effective weapons, and speculates she's using the tusk for Rule of Cool
  • Loyal Animal Companion: She tamed a Snow Stalker, calling it Preston. It is violently protective of her.
  • Sanity Slippage: She decides that going deeper and deeper below the surface is the way to solve things — and she starts stealing resources from the other two to either do it herself or force them to follow her. While it turns out she's right that the answers are deeper below the ocean, her threatening to leave Bart and Paul one man down and deprived of supplies, in addition to repeatedly causing trouble by being needlessly argumentative with Paul, was a step too far. This culminates when she somehow gets it in her head that towing a Reaper Leviathan to their base on their sub, still alive, is going to be a safe move and brushes off Paul's concerns that more Reapers will come down to save it. This is precisely what happens, culminating in their base being destroyed, Marguerit disappearing, Paul presumably drowning, and Bart seemingly spending his last days alone.
  • The Social Darwinist: Marguerit lives and breathes by this mindset.
    When sea monsters are hunting you, you don't hide. You hunt the sea monsters. Then you build a bigger boat out of sea monster bones, and you hunt bigger monsters. Keep going until there aren't any monsters left to hunt you.
  • Walking Spoiler: Most of these tropes spoil the fact that she survived the fate of the Degasi crew and appears in Below Zero.

Subnautica Below Zero Characters

    Robin Ayou 
Voiced by: Kimberly Brooks

The protagonist of the Below Zero expansion. An employee of XenoWorx, a company recently bought out by Alterra, Robin is looking for her sister Sam after the expedition she was a part of went missing and Alterra refused to send help.

    Sam Ayou 
Robin's sister. Her death on Planet 4546B is what motivates Sam to travel to said world, kicking off the events of Below Zero.
  • Everyone Has Standards: Sam very bluntly felt that the research on the Kharaa Bacterium sampls acquired from the Frozen Leviathan were stupid and went out of her way to try and administer the cure to the Frozen Leviathan so that the disease could be permanently stopped.
  • Taking You with Me: Detonates a bomb in the Phi Excavation Site, killing herself and Parvan Ivanov, while also forcing A Lterra to abandon the site.


An electric eel that will generally leave you alone unless you mess with it.
  • Bioluminescence Is Cool: Its eyes and the tips of its electricity-generating prongs glow.
  • Meaningful Name: The ampere is the base unit of electric current.
  • Psycho Electric Eel: If you annoy them, they'll arc electricity along their body as a warning before turning to actually attack you.
  • Shock and Awe: If two of them meet, they'll zap each other until one gives up and leaves.
  • Slippery as an Eel: Their bodies are actually rather joined and arthropod-like and the long prongs make them look decidedly less slippery.

A small, vicious tadpole-like creature.
  • Alluring Anglerfish: They have a little glowing lure on top of their heads.
  • Bioluminescence Is Cool: The tip of their lure glows, naturally, but the tips of their fins also glow a bit.
  • Dumb Muscle: The scanner claims it's 94% muscle, 4% connective tissue, and only 2% brain.
  • Exactly What It Says on the Tin: It bites you. A lot.
  • Extra Eyes: They have four eyes, two on each side of the head.
  • Goddamned Bats: They're really not that big of a deal. Solo. They can whittle you down in a surprisingly short time if you get ganked by several of them, however. And heaven help you if you needed every last bit of health to escape a Reaper and one of these little buggers bothered you first.
  • Monstrous Cannibalism: They're not picky when it comes to food when hungry, and they're always hungry, hence being mostly muscle to avoid being eaten even by their own species.
  • More Teeth than the Osmond Family: They have a ridiculous number of needle-sharp teeth for tearing you apart.
  • Piranha Problem: If they smell blood, they'll attack in swarms.

Passive fish, which can be used for food and water. They're also the only lifeform that can actually be directly crafted into something: their bodies can be used to create an air bladder tool, which can help get back to the surface quickly if need be.

A small, vicious suction-bulb-like creature.
  • Combat Tentacles: They possess retractable tendrils around their mouths that make harder to remove them while feeding.
  • Meaningful Name: They make you bleed, sucking both health and nutrition from your body.
  • Monstrous Cannibalism: If a Bleeder dies, the others in the area won't be averse to chowing down on the dead one's corpse. This can be exploited, as by killing one and dropping it back in the water with the Propulsion Cannon, other Bleeders will swarm and present themselves to you as open targets.
  • Piranha Problem: Like Biters, a pack of Bleeders can add up fast. Unlike Biters, Bleeders also drain your food, which means you can starve to death due to a parasite sucking all the nutrition out of you.

A brown variation of the Biter which lives in Blood Kelp.

     Blood Crawler
A large four-legged crab-like creature.

     Blue Barnacles 
A sedentary creature found hitching rides on Reefbacks. Classified as an animal because it is presumed to be a type of crustacean, just like Earth's barnacles.

A large, aggressive, heavily-armoured shark.

A small fish with very long, thin fins projecting from the top and bottom of its body, giving it a resemblance to a boomerang. If thrown, will not return.

     Cave Crawler
A four-legged crab-like creature that clings to floors, walls, and ceilings.
  • Bioluminescence Is Cool: The eye on its back glows.
  • Cyclops: It has a single, upward-facing eye on its back, likely to spot predators passing overhead.
  • Giant Enemy Crab: It's only about knee-high, but it's still rather large for a crab.
  • Meaningful Name: It crawls on four legs and is commonly found in caves (however, it's sometimes found a good distance outside them as well).
  • Spiders Are Scary: It resembles a spider as much as a crab, and is aggressive enough you'd be right to give it a wide berth.

A large, aggressive creature that resides exclusively in the Jellyshroom Caves.
  • The Symbiote: The PDA indicates that is acts as one with the Jellyshrooms (the giant mushroom-like plants it lives in) - in exchange for living inside the Jellyroom, it guards the plant from herbivorous predating and provides it with a constant source of food in the form of whatever pieces remain after it devours its prey.

An aggressive species found in the depths.
  • Angry Guard Dog: One of the most territorial creatures in the game, Crabsquids go ballistic on anything that enters their stomping ground. This trait, coupled with their sensitivity to light and their EMP blast, makes them the bane of anyone who's trying to set up a base in the resource-rich deep sea biomes they inhabitnote  Some players have exploited this through hatching a Crabsquid in containment and releasing it, which will make sure anything that used to threaten you, your base, your vehicles and your cameras will be a thing of the past.
  • Big Eater: Though never seen in-game aside from them trying to attack anything that moves and/or glows, their data bank entry states that Crabsquids do almost nothing else in their lives but stuff their giant stomachs day in, day out. Unfortunately, the Player Character is of the perfect crabsquid snack size.
  • Bioluminescence Is Cool: Its eyes, feet, several spots on its body, and the cracks on the stomach visible inside its clear outer membrane sack all glow. The general bioluminiscence of everything in the planet is likely also the reason why it's so attracted to lights, since light = alive = edible under most circumstances.
  • Bizarre Alien Senses: While it has large eyes and is attracted to light, it also makes clicking sounds for echolocation.
  • EMP: The Crabsquid possesses an EMP blast that temporarily shortcircuits machinery. Its actual, biological purpose isn't understood, though the PDA theorizes it has to do with shutting down Ampeel defenses.
  • Exactly What It Says on the Tin: It's a cross of a crab and a squid.
  • Extra Eyes: It has four eyes, like many of the game's animals.
  • Giant Mook: Crabsquids are among the largest non-Leviathan creatures in the game, dwarfing the Prawn suit and capable of being a threat to even the Cyclops.
  • Hero Killer: It's implied that a crabsquid is the creature that ultimately finished off Paul Torgal. The last Degasi Base is located in the Deep Grand Reef and is quite literally surrounded by crabsquid, and during the launch trailer, one of them attacks a human right as Bart mentions that his father was correct in suggesting going deeper was a bad idea. Its likely the crabsquid observed the destruction of the base and saw Paul as the easiest available meal.
  • Mix-and-Match Critters: Crab and squid, of course.
  • My Brain Is Big: Subverted. It looks like it has an enlarged brain underneath its transparent skin, but the database confirms that is not its brain but its stomach.
  • Shock and Awe: It can generate an electromagnetic pulse that can temporarily shut down vehicles and other electronics.
  • Shout-Out: Its vocalizations and EMP are straight from the MUTOs.
  • Suicidal Overconfidence: Possibly the only lifeform in the game that actively tries to eat Warpers. While certainly much bigger, trying to hunt prey that teleports is an exercise in futility or worse.
  • Throwing the Distraction: They're attracted to light, so tossing a flare will divert their attention from the player.

A small, spiny fish which lives inside the aptly-named Crash Plant. If disturbed, it will pop out and attack the player.
  • Action Bomb: Their means of attacking is to swim up to the player and explode.
  • Bioluminescence Is Cool: Its fins glow brightly, but the red scales on its back also exhibit a faint glow.
  • Expy: Share more than a few similarities with Minecraft's Creepers.
  • Glass Cannon: They can destroy your vehicles thanks to a chemical reaction in their spines and deal a great amount of damage to you if you're swimming alone, but they can only attack once and are easily incapacitated with the Stasis Rifle.
  • Meaningful Name: Its sole purpose is to crash into potential aggressors, including the player or their vehicle.
  • Suicide Attack: They'll blow themselves up a few seconds after launching themselves from their nest.
  • You Will Not Evade Me: Once you hear their scream, good luck avoiding their attack without the Ultra Glide Fins.

     Crimson Ray
A subspecies of the Ghostray. Exclusively inhabits the Inactive Lava Zona and Lava Lakes.
  • Bioluminescence Is Cool: Unlike the other species of Ray in Subnautica, it possesses very little Bioluminescence, in that the only parts that glow are its eyes and gill slits.
  • Exactly What It Says on the Tin: The top side of the creature has a crimson pattern.
  • Gentle Giant: It is the same size as the fairly large Ghostray; despite this, the animal is completely and utterly harmless.
  • Palette Swap: Of the Ghostray.

     Cuddle Fish
A small pet-type fish, originally known as the Cutefish. This critter was the original design for the Crash, but the developers decided it was too cute for the role and made it into a pet instead.
  • Exactly What It Says on the Tin: Its old name was the Cutefish, and it's a cute fish. Its function is to be cute. The current name is also rather appropriate, as it has a remarkably cuddly appearance for a half-squid creature, and indeed you can pet and cuddle it when playing with it. If you never release it into open water you can actually take it home with you to huge and pet and play with forever!
  • Friendly, Playful Dolphin: Has some porpoise inspiration in its design, makes squeaking noises similar to a dolphin, and is indeed friendly and playful. It's also curious and intelligent, being able to both be intrigued by, and express amazement at, the old "coin behind your ear" sleight of hand trick.
  • Killer Rabbit: Back when it was meant to be the Crash, it was this. Now it's perfectly harmless.
  • Mix-and-Match Critters: It resembles a very small porpoise crossed with a squid.
  • Punny Name: Of the real life cuttlefish, who aren't as cuddly.
  • Ridiculously Cute Critter: The alien fish equivalent of a panda. It also chirps like a small bird. May be considered Ugly Cute if you don't find squid appealing.

A small, simple creature composed of an eye and a few fins.
  • Butt-Monkey: Some creatures just shove them around without even eating them.
  • Bioluminescence Is Cool: The fins behind its eye glow.
  • Cyclops: Its body is 90% eyeball. A single eyeball.
  • Meaningful Name: Its most salient feature is its eye.
  • Oculothorax: In addition to its giant eyeball, it's got a few little fins that trail behind it. That's it, though; it doesn't even have a discernible mouth.

A floating creature which attaches itself to rocks, lifting them up towards the surface.
  • Attack of the 50-Foot Whatever: Most floaters are small, about the size of a coconut. You can also find a giant variety that's several times your size. Interestingly, the giants are less destructive: while floaters are not aggressive, they are indiscriminate in what they attach themselves to, and so strongly buoyant that they can drag even your Cyclops around. The big ones are already attached to their rock, and big enough that they won't be dislodged by anything, meaning they won't ever get in your way as the little ones can.
  • Bioluminescence Is Cool: The pink inner body glows slightly.
  • Exactly What It Says on the Tin: It floats. That's about it.
  • Lamprey Mouth: The bottom of the creature is a sucker mouth. Its "teeth" actually appear rather soft and rounded, however.
  • Turtle Island: A few of these have grown to a gargantuan size, holding up several underwater landmasses alongside what is easily the biggest island in the game.

A slow-moving fish that putters around the shallower areas. It's fairly easy to catch.

A large, slow creature that resembles a manatee with a bloated, bulbous tail. Typically ignores the player, but will expel Gas Pods that explode into clouds of toxins if bothered.
  • Beware My Stinger Tail: The tail and even the animal itself is not dangerous. However, it is home to a symbiotic species of algae which produces a very caustic acid, and when startled the Gasopod tenses its muscles and expels pods of the stuff.
  • Bioluminescence Is Cool: Its eyes and the gas pods on its tail glow.
  • Fartillery: The gas it releases will paralyze fish and damage you or your vehicles. If you grab the pods before they explode, you can keep them in your inventory and use them as improvised weapons or as an ingredient for the Gas Torpedo.
  • Gas Mask Mooks: Their trunk resembles a gas mask. It also functions as one, with multiple pairs of gills capable of filtering and detoxifying the gas from its tail.
  • Gasshole: Its species hat.
  • Living Weapon: The gas is actually produced by symbiotic algae that live in the Gasopod's tail.
  • Meaningful Name: The gas-releasing pods on its tail are its most noteworthy feature.

A big, glowing creature that resembles a translucent manta ray. Exclusively inhabits the Lost River.
  • Bioluminescence Is Cool: The entire animal glows, including the organs seen through its translucent body.
  • Exactly What It Says on the Tin: If a manta ray was reincarnated into a glowing, spectral entity, it would be this Ghostray.
  • Gentle Giant: The entire ray itself is several times larger than a human; despite this, the animal is completely and utterly harmless.

     Ghost Leviathan
The Ghost Leviathan is a huge, translucent, hammerhead-eel-like beast that calls the Lost River and a few other biomes home. Like the other leviathans (barring the Sea Emperor), it is a very dangerous beast.
  • Angry Guard Dog: One hell of a guard dog, for sure. Ghost Leviathans are incredibly territorial, requiring singular dominance over a considerable space in order to feed. Anything they regard as challenging them for ownership is met with incredible force, with the intent of driving it off. note 
  • Bioluminescence Is Cool: Notable for being the only aggressive Leviathan species to exhibit this trait to a relevant degree. Its four eyes glow a golden orange colour, as do a series of light-tipped stalks and lines of light along the inside of its body. The entire body also emits a faint blue glow that's hard to notice unless the surroundings are pitch-black, like the Crater Edge for instance, which makes for an incredibly chilling sight that probably gave them their name.
  • Border Patrol: They have been implemented in the Crater Edge now, and they're fully-grown adults. They're also far more aggressive than the others on the Crater and will relentlessly chase the player until they're dead or back in the map. Up to three can be chasing you at one time, as many adults as are normally spread around the entire map.
  • Extra Eyes: Possesses four eyes, like many creatures on the planet.
  • Hitbox Dissonance: As with other long-bodied creatures in the game, only its head is vulnerable to any damage.
  • Hunter of Their Own Kind: The Juvenile Ghost's data bank entry posits that they feed on anything they can get their jaws on, including unfortunate members of their own species, until they grow too large for their nursery grounds, leave for open waters and turn into filter feeders. Doesn't affect their in-game behaviour in any way, but it should tell you all you need to know about what to do when you encounter these creatures.
  • Killed Off for Real: The ones living in the Crater will not respawn if killed.
  • Meaningful Name: Much of its body is translucent with a more solid body structure inside, giving it a ghost-like look. The way its mouth opens also closely resembles a Ghostly Gape.
  • Ramming Always Works: Unlike the other aggressive Leviathans, which have limbs of a sort, the only weapon a Ghost has is its armoured head, which it can use to devastating effect.
  • Sea Monster: It's the fourth Leviathan-class creature in the game, and just as deadly as the Reaper and Sea Dragon. It's also the third-largest creature in the game after the Emperor and Sea Dragon. Disturbingly, unlike the Reaper and the Sea Dragon, the Ghost doesn't attack to eat you, since it's a filter feeder; it attacks to ward you off from its territory.
  • Use Your Head: Due to its eel-like build and lack of teeth, Ghost Leviathans attack with what is essentially the most terrifying headbutt in recent gaming history.

A very small fish with a hole through its tail. By manipulating the size of the hole, it's capable of unexpectedly changing directions, making it difficult to catch.

A very identifiable fish with a "hoop" of flesh that extends from nose to tail along the top of and bottom of its body.
  • Bioluminescence Is Cool: One of the brightest fish in the sea. Its most striking feature is the glowing green hoop that extends around the top and bottom of its body from nose to tail, but its fins and body spots also glow.

A small, reptilian lifeform often found swimming around plant life.
  • Bioluminescence Is Cool: Its "feet" and the spots on its back glow.
  • Meaningful Name: It "swims" by ionizing the surrounding water, allowing it to "hover" over the sea floor.
  • Non-Indicative Name: Despite being called a Hoverfish, the description of its cooked form says it has reptilian flesh. Coupled with the appearance of its face up close, it appears to actually be more of a Hoverseaturtle.
  • Ridiculously Cute Critter: While not as aggressively cute as the Cuddle Fish, many fans have taken a shine to the Hoverfish thanks to it's adorable, smiling face and being curiously emotive for such a small and simple creature. Some have expressed a desire for Hoverfish to be able to be adopted and interacted with in a manner similar to the Cuddlefish.
    • Adorably, they actually seem to develop an affection for the player if kept in an Alien Containment. Hoverfish can be observed swimming up to the player and "dancing" with a huge smile on their face.

Another big, glowing creature that resembles a cross between a stingray and a jellyfish.
  • Bioluminescence Is Cool: The entire animal glows.
  • Exactly What It Says on the Tin: If a jellyfish and a stingray had a baby, it would be this Jellyray. The only way its name could get more accurate is if you called it a glowing Jellyray.
  • Gentle Giant: The central core of its body is about as big as a human; the tentacles and tail streaming behind it are much longer. Despite their pointed tips and its resemblance to a jellyfish, the animal is completely and utterly harmless; it is neither aggressive nor in possession of stinging nematocysts.
  • Mix-and-Match Critters: Stingray and jellyfish.

     Lava Larva
A small grub-like life form found in the Inactive Lava Zone. They will grab onto your vehicles to suck out power and potentially strand you in the depths.
  • Bioluminescence Is Cool: Its eyes, mouth, and a streak along its belly glow.
  • Bizarre Alien Biology: They completely lack a digestive tract, sucking the energy they need to survive directly out of their prey instead. It's unknown what exactly they feed on when there aren't any human castaways invading their territory with fancy machines.
  • Lamprey Mouth: Its mouth (visible on the underside of its body) is a teardrop-shaped ring of teeth.
  • Meaningful Name: It's found near lava and is apparently the larval form of a larger creature.

     Lava Lizard
Shown here sans armour.
An aggressive species of aquatic lizard that is capable of swimming in lava and even gathering it onto its back to use as armour and ammo. Found only in the Inactive Lava Zone.
  • Bioluminescence Is Cool: One of the few aversions, as the animal itself, doesn't glow. However, after diving into lava, it carries around glowing, molten coals on its back.
  • Fangs Are Evil: Or at least a very good indicator of aggression.
  • Lava Adds Awesome: It's already aggressive and toothy, but swimming in lava grants it the ability to shoot fiery rocks.

A subspecies of Boomerang that lives in the Inactive Lava Zone.
  • Lava Adds Awesome: Is exclusively found in the Inactive Lava Zone, where its' colouring and bioluminescence is evolved to make it visually blend into the volcanic formations and lava channels.
  • Genre Savvy: Its colouring and bioluminescence makes it blend in to the volcanic formations and lava channels. Given that there are two Sea Dragons down there, this is an exceptionally smart idea as it avoids being eaten as it cannot be seen.
  • Palette Swap: Of Boomerangs.

A creature which somewhat resembles an underwater butterfly when it attacks; when at rest, it folds its fins away.
  • Bioluminescence Is Cool: Its large fins glow. Unlike other species, the precise function of the glow is known: it mesmerizes anyone stuck in front of it, leaving them open for attack.
  • Charm Person: Despite being no bigger than an average dog, its true danger lies in the fact that you can't even risk looking at it for long before it tries to hypnotize you and take a huge bite when you get too close.
  • Interface Screw: The glowing patterns on the Mesmer's fins are so hypnotic it becomes difficult to wrench your eyes away from it, mechanically reflected by the camera being forced to center on it while nearby unless the player can turn themselves entirely away or get enough distance.
  • Mission Control Is Off Its Meds: Invoked by the Mesmer's Charm Person ability. The Mesmer cannot talk, but it can cause you to hallucinate that your PDA computer is talking to you, telling you to your primary directive is to swim closer to that beautiful creature. This even extends to its Data Bank entry:
    The Mesmer can open the jawlike recess in its protective outer shell in order to [ERROR463] share its beauty... Do not resist...

    Assessment: Draw closer.
  • Nested Mouths: Its entire face splits open to reveal four tentacle-like appendages lined with teeth that lead to its actual throat.

A slightly larger version of the Peeper that lives exclusively in the Jellyshroom Caves.
  • Bioluminescence Is Cool: Its eyes glow.
  • Bizarre Alien Biology: The PDA speculates that it feeds on the soft caps of the Jellyshrooms, though how it does so is unclear since it lacks any visible mouth.
  • Item Farming: Oculus make the best bioreactor fuel of any edible fauna and a decent meal on top of that, making them a good choice for breeding in Alien Containment.
  • Life-or-Limb Decision: According to the PDA it can detach its tentacles to distract predators in a manner similar to a lizard dropping its tail.
  • Underground Monkey: It's a slightly larger subspecies of the Peeper, adapted to living in Jellyshroom caves. The two are still closely related enough to breed with each other if placed in an alien containment unit together; said offspring will always be more Oculus.

A small, swift fish. Out of all the species in the game, it's probably the closest to what the average person would think of when they think "fish".
  • Bioluminescence Is Cool: Its eyes glow.
  • Chekhov's Gunman: The Peeper as a species is probably secretly the second most important creature in the game, after the Sea Emperor herself. Under her command, they not only converted the aquarium into a thriving ecosystem but single-handedly stopped the Kharaa from completely destroying the planet.
  • Foreshadowing:
    • The PDA is quick to point out that the Peeper has a lot of evolutionary traits irrelevant to any of its habitats. This is because they're secretly the Sea Emperor's underlings, who evolved them into a heavily customized form fit for delivering the cure to the world.
    • The one these adaptations are the holes on the side of the peeper, which lets it expel the contents of its stomach. The PDA cannot fathom a biological reason for it. Peepers can be seen doing it sometimes in-game, leaving glowing trails behind them. It's how they deliver the cure.
  • Helpful Mook: They're not actually 100% natural creatures. They're an entire species of underlings for the Sea Emperor, tailor-made through evolution, and their one job is to collect flora to keep the Emperor's aquarium functioning, and deliver the cure to the surface to fight off the Kharaa.
  • Meaningful Name: You cannot miss a school of Peepers' peepers if your own function at all. They're probably also little info-gatherers for the Sea Emperor. Which is probably why she can reach out to chat to you at all. When the PDA warns you about the possible intellects of creatures you study in containment, the Peeper is one likely candidate. It watches you: check its animations when you idle nearby.

     Rabbit Ray
Small harmless fish that swim close to the seafloor. They are inedible.

     Reaper Leviathan
Large hostile creatures that patrol several areas of the surface section of the world, especially around the remains of the Aurora, though they also call the Mountains and Dunes their home.
  • Artificial Stupidity: The Reapers in the Dunes biome aren't the most intelligent of the Reapers in the game. They'll often ignore you even when you're close by, and when they do move in to attack more often than not they'll straight-up miss, especially if you're on the sea floor inside or outside the Seamoth/PRAWN. By contrast, the ones in the Crash Zone and the Mountains will see and chase after you relentlessly if you get in range. Though even the former can have a massive brain fart and get their faces stuck in the half-melted girders around the prow of the Aurora, roaring in place at nothing in particular.
  • Angry Guard Dog: Not technically a guard dog, but this monster likes to hang around the Aurora at the Crash Zone and the Quarantine Enforcement Platform at the Mountains more than any other creature. The Dunes entrance to the Inactive Lava Zone was closed off, but the Reapers there now have a meteor impact crater with a Precursor Cache and a sinkhole containing a Cuddlefish Egg to patrol around.
  • Bioluminescence Is Cool: Notable for being one of the few species on the planet to mostly avert this. They possess ZERO bioluminescence, making them practically invisible at night until they're right in your face. The red parts of their body used to exhibit a very faint glow, but that changed once they received a new model.
  • Dumb Muscle: If you can manage to scan one, the results claim that it has very little brains, "just muscle, synapses and teeth."
  • Eaten Alive: If it catches you outside a vehicle at below 80% health, it'll just stuff you in its mouth whole. To add insult to injury, it first roars in your face.
  • Extra Eyes: Like so many creatures, it has four eyes instead of two.
  • Extreme Omnivore: It'll munch on your Seamoth or other vehicles as well as you or any other lifeform.
  • Foe-Tossing Charge: Reapers will move their prey a considerable distance away from where they initially grabbed it during their attack animation, which can be more annoying than the damage they deal upon the vehicle you're in. It can also end in them smashing your ride against the sea floor or some other large obstacle for a One-Hit Kill, although it's more likely they'll glitch you through the map instead.
  • Hero Killer: Reapers were responsible for the deaths of 2nd Officer Keen, CTO Yu, the unnamed occupant of Lifepod 4, and Marguerit Maida.
  • Hitbox Dissonance: As with other long-bodied creatures in the game, only its head is vulnerable to any damage.
  • Informed Ability: The scan data claims that its deep roars are echolocation ("if you can hear it properly, the Reaper can see you") but they don't actually work like that in-game.
  • Jump Scare: The most likely deliverer of them in the game. Reapers are the only creatures that don't just attack but have an actual, prolonged, almost inescapable grabbing animation when they do so. You're cruising around in your Seamoth, minding your own business, when suddenly one of these beasts appears out of nowhere, grabs your sub, turns it around so you're face to face, emits a bone-chilling roar, and proceeds to do unpleasant stuff to your poor ride. You can be forgiven for needing a change of pants the first times you witness this (especially while playing in VR), and it doesn't really get less scary afterwards. Keep in mind that the Reaper's constant roars announce their presence from quite some distance away, and still their attacks are scary as hell. Nice going, devs.
  • Killed Off for Real: As with other Leviathan-class creatures, if killed, they will not respawn.
  • Lightning Bruiser: Swims faster than the Seamoth, and treats it like a chew toy.
  • One-Hit Kill: If you ever encounter this creature, there's a high chance that it will kill you. It will also destroy your Seamoth in two hits if it gets a hold of it, and in one hit if it gets to perform its smash-against-obstacle attack. The latter also instakills the Prawn suit.
  • Roar Before Beating: You'll likely hear the Reaper Leviathan before you see it. Once you do, get to safety.
  • Sea Monster: One of the few monsters that can attack and kill you if you get spotted by it.
  • Shout-Out: Possibly to Slattern, with the tentacles attached to the torso with arms. The movie did come out before the game was initially released in Early Access in 2014.
  • Slasher Smile: The thing always looks like it's sporting one hell of a nasty grin. One could think it knows you're browning your briefs whenever you realize it knows you're there, but seeing how Reapers seem to lack any brain whatsoever, it's probably just evolution playing one of its mean jokes.
  • Super-Persistent Predator: One of the only animals that will follow you for a long time. They still give up after a while.
  • The Worf Effect: There are several Reaper skeletons in and around the Lava Zones. What killed them? THE SEA DRAGON LEVIATHAN!

     Red Eyeye
A subspecies of Eyeye that lives in the Inactive Lava Zone.

     Reefback Leviathan
Giant creatures that occasionally swim through the world. Big, slow, and generally harmless.
  • Bioluminescence Is Cool: Its fins and eyespots glow.
  • Dummied Out: Reefback eggs are fully coded into the game and can be hatched inside alien containment units, but they have the same model as Spadefish eggs and are only obtainable with the debugging console, as they will never naturally spawn anywhere in the game world.
  • Gentle Giant: Despite their massive size, they're one of the least hostile creatures - namely that they never attack you, ever and about the only way one can be a threat to you is if a Tiger Plant takes root on its back, and even that can be mitigated by wearing a Reinforced Dive Suit.
  • Helpful Mook: The glowing blue barnacles on their backs can be smashed apart to get copper or silver, both of which are extremely valuable resources.
  • Turtle Island: Big enough that entire ecosystems have taken residence on their body.

A creature which resembles the real-life sunfish. Also a distant relative of the Peeper.
  • Bioluminescence Is Cool: Its fin glows.
  • Bizarre Alien Biology: It has four gill-like slits for eating instead of a mouth.
  • Item Farming: Reginalds are a very popular choice for farming in an Alien Containment, since they restore the most food of any edible fauna. They also make good bioreactor fuel, second only to the Oculus in output when compared to other edible fauna.

     River Prowler
A large, aggressive eel with a transparent body that reveals its spine. Its internal organs are also apparently transparent, and its digestive processes are quick and efficient, rendering food a transparent soup upon swallowing. Spawns in the Lost River Bones Field.

The smallest creature currently implemented; it lives inside caves and is harmless.

     Sand Shark
A large, aggressive shark-like creature which burrows into the sand and pops out to snatch prey. And yes, you're on the menu, too.

     Sea Dragon Leviathan
An even greater enemy than the Reapers, two of which reside in the Inactive Lava Zone and one which dwells within the Lava Lakes. One of them, whose eggs were being held in the Lost River Disease Research Center, was the cause of the release of the Kharaa bacterium into the environment, ramming the facility with her head and causing extensive damage in an attempt to reclaim her eggs. Her skeletal remains lay just outside the entrance to the cavern the Disease Research Facility is in.
  • Big Bad Duumvirate: There are a total of three in the game, and collectively they are at least partially responsible for spreading the Kharaa Bacterium that their posthumous mother unleashed. You will have to get past them if you want to cure the planet and yourself. Watch out for the one guarding the Primary Containment Facility since it will ignore the deterrent devices if you look interesting enough.
  • Bioluminescence Is Cool: Its eyes, the tips of its nose horns, and several little spots along the sides of its body and tentacles glow.
  • Dying Race: According to the PDA they are at risk for extinction, possibly due to the Kharaa wiping out most of their larger food sources. They definitely deserve it.
  • Eaten Alive: A very real possibility, if you happen to cross its path. Unlike the lesser Reapers, these guys are big enough to just swallow you whole for an instant kill.
  • Extra Eyes: Like many of the animals, it has four eyes.
  • Extreme Omnivore: It'll munch on your Seamoth or other vehicles as well as you or any other lifeform.
  • Foil: To the Sea Emperor. The Sea Emperor on its dying breath wishes you good intentions, was not actively malevolent, and in general seemed to be very kind in general with her kids being part of the future for the planet. By contrast, the Sea Dragon Leviathan was actively trying to get into a lab and steal back it's eggs, damning the planet, and overall seems more vicious. Even it's offspring show this as they're fully grown and attack all animals along with spreading a dangerous virus while the Emperor's young are still infants and will produce an enzyme that counteracts the virus the Sea Dragons spread.
  • Giant Squid: The back half, at least. Like most fictional giant squids, it's vicious.
  • Hero Killer: Implied to be what ultimately killed Marguerit Maida, as its roar is heard just before the last Degasi Base is attacked.
  • Mama Bear: The mother of the eggs that the Architects had grabbed attacked and breached the Disease Research Containment Facility, causing the Kharaa virus to spread throughout 4546B.
  • Mix-and-Match Critters: Its front half clearly resembles typical dragons, while the back half is a squid.
  • Monster Is a Mommy: The Sea Dragon that started the apocalyptic infection of the planet wanted her eggs back and attacked the Disease Research Facility to free them.
  • Never Smile at a Crocodile: It has the crocodilian "smile" to its jaw structure, making it look like it's grinning as it comes after you.
  • Playing with Fire: It breathes fire. Yes, underwater. Though instead of actual fire it spits red-hot rocks and molten materials from its mouth, the PDA data mentioning that it consumes such material for that purpose as well as making itself resistant to heat.
  • Posthumous Character: The mother Sea Dragon passed away hundreds of years ago. However, her three descendants are alive and hungrier than ever.
  • Sea Monster: Even meaner than the Reaper. How much meaner? There are several Reaper skeletons and skulls laying in the huge chamber of the Inactive Lava Zone that holds the Lava Castle, connects to the Lost River, and where two Sea Dragons patrol. The Sea Dragon EATS REAPERS. Also, it has ties to the Lost River's skeleton.
  • Shout-Out: The colossal reptilian and the clawed serpents it feeds on are both very similar to sea monsters from The Phantom Menace, and have a very similar dynamic.
  • Unwitting Instigator of Doom: Sometime in the past, the Precursors took in some Sea Dragon eggs for study, angering the mother who proceeded to attack the Disease Research Facility housing them. This caused a breach that would spread the Khaara to the rest of the planet.

     Sea Emperor WARNING - SPOILER ALERT!!!
"A game played alone... cannot be won. Those that took my freedom played to live... forever. Such games can only be lost."
—The first of the decoded cries from the Emperor

Voiced by: Lani Minella

The largest sea creature. One specimen was captured by the Precursors and held in the Primary Containment Facility by the Lava Lakes and is the Last of Its Kind. As it turns out, the species produces an enzyme that cures The Plague covering the planet. However, global administration cannot happen with only one producer, and thus the Precursors forced it to breed in order to create more specimens and produce more of the cure. As a sapient species, it was able to develop the common traits of the cries of the planet's fauna into a language that it uses to speak to the player.

  • Aliens Speaking English: Subverted. Despite being able to "talk" to the player, the PDA implies that it is a rudimentary language shared among Planet 4546B's fauna.
  • Ambiguous Gender: its voice sounds female, but it's suggested to be a simultaneous hermaphrodite like the rest of the life on the planet.
  • Big Good: It's been working to stop the Kharaa for centuries by giving Peepers the cure.
  • Bioluminescence Is Cool: Like the Sea Dragon Leviathan, it eyes, horn tips, and body spots all glow.
  • Extra Eyes: Like many of the animals, it has four eyes.
  • Face Death with Dignity: The Emperor is very much aware of its situation as a captive and that it doesn't have long to live. Knowing that you will release its offspring and cure the Kharaa bacterium, though, it seems content to pass on.
    Sea Emperor: My young are swimming for the shallows. I thank you. Their freedom is my end.
  • Foreshadowing: In Bart Torgal's final log, he mentions that "the visions are getting worse". It seems likely that the Emperor was trying to speak to him as she does the player, but he died before figuring it out.
  • Gentle Giant: The Sea Emperor is the largest creature in the game but, unlike the Reapers and Sea Dragon, does not actively try to hurt you. In fact, when you first encounter it, it telepathically communicates with you about saving its eggs.
  • Go Mad from the Isolation: Surprisingly averted. The poor thing has been alone in a comparatively tiny aquarium for well over a millennium, but this isolation doesn't seem to have had any negative effects on its psyche. It's implied it can talk to the other fauna in its tank, so hopefully, its loneliness only extended to its own species.
  • Hidden Depths: It's very philosophical for a giant sea monster. It's difficult to tell if this is a trait of its species or if its a by product of her extremely long life.
    What is a wave without the ocean? A beginning without an end? They are different, but they go together. Now you go among the stars, and I fall among the sand. We are different. But we go together.
  • Interspecies Friendship: Clearly considers you a friend. Its final speech even implies it believes the two of you are two parts of a greater whole, perhaps making you a platonic version of soulmates in its eyes.
  • Last of Its Kind: After the destruction of their planktonic food supply from the asteroid impact and Kharaa left the rest of the Emperor's species dead, it's the only one left and is being held captive in the Lava Lakes so that it can breed and re-populate its species, since they produce an enzyme that cures the virus on the planet (child Emperors are implied to produce the enzyme at around four times faster as aged specimens and in a more concentrated form, hence the need to produce them.)
  • Leaning on the Fourth Wall: In much of its dialogue. It refers to life as a "game", and to living as "playing".
  • MacGuffin Super Person: To the Precursors, as its species was capable of producing a cure to the Khara bacterium that was ravaging their empire and it was the Last of Their Kind. It becomes this to the player too for the same reason.
  • Miles to Go Before I Sleep: The Sea Emperor was already ancient by its species' standard when it was caught, and it's endured for another 1,000 years past that point when you meet it, only so it can make sure its young hatch, its species survives, and with it the rest of the planet. True enough, it collapses barely a minute after its babies have left for the shallows, and it's implied it finally passes on after its last telepathic conversation with the Player Character.
  • Nothing Left to Do but Die: Once its young hatch, it can finally allow itself to die in peace.
  • Purple Prose: The Sea Emperor's dialogue is quite flowery, speaking almost entirely in metaphors about its time in captivity and what the Precursors were doing to it.
  • Reincarnation: it apparently believes in it:
    Perhaps next I will play as an ocean current, carrying seeds to new land... or a creature so small it sees the gaps between the grains of sand.
  • Sealed Good in a Can: The Sea Emperor species is the only thing that can stop the Kharaa.
  • Sea Monster: Albeit not necessarily aggressive.
  • Telepathy: It can communicate with certain other lifeforms this way. The Player Character is one of them, but unfortunately for everyone it couldn't contact the precursors back when they captured it. If it had, the situation on 4546B would've taken a completely different turn ages ago.
  • Time Abyss: it was over 1,600 years old (well past the peak lifespan for its species) when the Precursors captured it. That was more than 1,000 years ago.

    Gargantuan Fossil Leviathan 
An absolutely gargantuan creature that once lived on Planet 4546B, the remains of this beast take up an entire section of the Lost River.
  • Hope Spot: The notes in the Disease Research Facility imply that it might have been able to cure the Kharaa Infestation, but the Architects didn't have enough genetic material to create a live specimen.
  • Kaiju: The biggest creature encountered in the game, even if it is long dead. In fact, given the PDA Notes on the Sea Emperor, this is probably the single largest creature in the entire Subnautica universe. To put this into context, its skeleton is over a kilometer in length,
  • Kraken and Leviathan: The largest creature in the came, and possibly the largest creature in the Subnautica universe.
  • Mascot Mook: Its skeleton is the same one visible on the cover of the game.
  • No Name Given: As it is never encountered alive, it is only referred to by the designation given to it by the PDA (Gargantuan Fossil) and the Precursors (Large Carnivore Theta).
  • Posthumous Character: It died before any of the plot events happened, with only its skeleton as a reminder that it existed. Died millions of years prior to the game, but it's implied to be the reason the Disease Research Facility was built.
  • Reality Ensues: How did this thing die? Based on the available information, it became trapped in the Lost River and starved to death due to being unable to sustain itself on the native fauna.

     Sea Treader Leviathan
A giant, walking creature that picks its way along using its two hind legs and sucks up plants from the seafloor using its long neck and mouth.
  • Bioluminescence Is Cool: Its antennae glow, as do some of the orange patterns around its body.
  • Giant Enemy Crab: It's a crustacean in appearance, though without claws.
  • Gentle Giant: It won't attack you out of malice or predation, but if you get too close it will take a swing at you.
  • Helpful Mook: They kick up an unlimited amount of shale deposits as they walk, giving you an easy, safe supply of diamonds and lithium. Plus, their droppings make excellent fuel for a bioreactor.
  • The Last of These Is Not Like the Others: It's classified as a Leviathan life-form by the PDA, but it's the first of its class that's non-hostile. It will only attack you if you come too close, otherwise, you'll be left alone.
  • Tripod Terror: Two legs in the back, a very elongated head and mouth in front. Not very terrible, though, unless it kicks you.

A small, harmless cave-dweller.
  • Bioluminescence Is Cool: The orange patterns on its body glow.
  • Notice This: They tend to hang out at the entrances of smaller but confusing underwater caves, that combined with their bioluminescence can help you find them if you need to cave-dive or serve as markers to find your way out.

A bird-like creature which can be seen flying above any places with dry land (or sufficiently large ships, such as the Aurora) projecting from the water.
  • Bioluminescence Is Cool: The undersides of its wings glow.
  • Disturbed Doves: When you complete the Neptune, the countdown to launch shows a flock of skyrays perched on the nose of the rocket. They fly away when you take off.
  • Super Drowning Skills: It can't stand being underwater at all. This includes if you use console commands to spawn it inside your base; apparently, the mere presence of water above it — despite being in an oxygenated base — is enough to make it drown.

A flounder-like fish. It's fairly slow, making it a reasonable source of food.

A deep-water relative of the Hoopfish that resembles a skeleton, but is just as harmless and tasty as its shallow-living cousin.

A big reptile that patrols the kelp forests. It's attracted to both metal and organic objects smaller than itself; both are potential meals.
  • Extreme Omnivore: They eat scrap metal, which is incorporated into their teeth.
  • Genius Bruiser: Despite being large and aggressive, the Stalker is one of the more intelligent lifeforms on the planet. If you feed it fish or metal, it will remember you for a bit and not attack.
  • Never Smile at a Crocodile: It resembles a real-life gharial.
  • Teeth Flying: They'll frequently bust off some of their teeth when they're trying to chew on metal, especially if they try taking a bite out of a Seamoth. Good for you, because you need those teeth to create reinforced enamelled glass.

A strange creature capable of ripping holes in the fabric of reality and opening portals to other locations on the planet. Its origins and true functions are largely unknown and cannot be verified by the PDA.
  • Aliens Steal Cable: Inverted. Sometimes your radio will intercept messages from the warpers as they relentlessly hunt down the Aurora survivors. The first such message, partially translated, establishes that they're patrolling the area. The second transmission reveals that the player is now their priority target. The third transmission is completely incomprehensible.
  • Big Bad Duumvirate: They're the closest thing the game has to proper antagonists, being the only aggressive species that targets the player specifically.
  • Bioluminescence Is Cool: Its eyes and veins glow brightly, while the membranes surrounding it also have a faint glow.
  • Cyborg: Created by infusing technology into an unknown species. Its organs are equipped with hardware to improve processing power and bugged with remote communications, and their skin contains a miniature phase-jumping system.
  • Final Solution: Built to kill all infected fauna not under quarantine.
  • Guttural Growler: Their "voices" are deep and gruff.
  • Heel–Face Turn: When The Player cures themselves of the bacteria they cease their hostility.
  • Hero Killer: They are implied to have killed off most of the Aurora survivors, and in the latter half of the game they target you specifically.
  • Implacable Man: Very much so. They're almost always somewhere nearby, and even if they're not attacking you, they tend to follow you from a distance just to keep an eye on you.
  • Non-Malicious Monster: They're simply following what they were engineered for. Once the player is cured, they are quite passive, and potentially helpful at warding off aggressive wildlife.
  • No-Nonsense Nemesis: While stalking and roaming, they're much less noisy than other lifeforms on the planet. If you didn't see 'em right away, the first warning there's a Warper in the area is usually you being violently teleported. Which make sense, since they were literally made to kill.
  • Screw This, I'm Outta Here!: If you actually try to attack them, either with a weapon or simply ramming them with a Seamoth, they will make an electronic screech and warp away. It's pretty hard to actually kill them as a result.
  • Summon Bigger Fish: Literally. Sometimes they will summon hostile fish to distract you, depending on whatever biome you're in.
  • Teleport Spam: Their signature ability, hence the name.
  • Those Two Bad Guys: They almost always spawn in pairs, working together to take you down.
  • Zerg Rush: If you approach any of the Precursor bases, expect to be mobbed by these things at a much faster rate than normal.

Arctic Mega Biome Creatures

    Arctic Peeper

A polar version of the peeper.

    Arctic Ray

A ray subspecies that spawns in the Twisty Bridges.

  • Informed Ability: The PDA designates the Arctic Ray as a herbivore, but its teeth are better suited for preying on smaller fish.

    Arrow Ray

A triangle-shaped fish that spawns in the Lilypad Islands and Tree Spires.


A small predator that can shoot a freezing liquid at its prey to encase them in ice.

  • Mix-and-Match Critters: It looks like the head of a seahorse planted on a flying fish. Plus, the spitting attack is the exact same as the real-life archerfish.
  • Super Spit: It can spit a sub-zero liquid at prey and predator to freeze it. And yes, this includes you.

    Brute Shark

A predatory creature native to the Arctic Mega-Biome. Only found in the Twisty Bridges.

  • Never Smile at a Crocodile: In addition to having shark traits, its head also vaguely resembles a crocodile. Unlike the Stalker, though, it isn't capable of being tamed.
  • Threatening Shark: Resembles a ray, but is just as aggressive and hungry as any shark.

Void Chelicerate

A leviathan-class predator resembling a cetacean-shaped crustacean with massive mandibles. At the moment it spawns only in the Purple Vents biome, a fairly shallow area with thermal vents.

  • Border Patrol: A special kind of Chelicerate, known as the Void Chelicerate, serves this purpose in Below Zero.
  • Extra Eyes: Has four eyes like most of the planet's inhabitants. The larger pair are black and have white glowing rings in them, while the smaller pair are completely black.
  • Giant Enemy Crab: Well, half-shrimp.
  • Mix-and-Match Critter: The shape of its body resembles a dolphin including flipper-like translucent fins, it's covered by a shrimp's multi-jointed shell with a shrimp's fluke-like tail fins, and its mouth is hidden in-between two massive pairs of jagged-edged black mandibles resembling a camel spider's mouthparts.
  • "No. Just... No" Reaction: Their databank entry basically says that not a lot is known about the Chelicerate, and many on Planet 4546B would like it to stay that way. Given what it can do, we can't say we blame them.
  • One-Hit Kill: Only if Robin is at less than 80 health, similar to the Reaper Leviathan. Between 100 and 81 health it does a powerful snap with its mandibles dealing 80 damage. Any less and you get to watch Robin be gripped by the mandibles, pound on one futilely as the mouth opens, then tumble helplessly into its throat as its mandibles release.
  • Sea Monster: Like most of the rest of its classification, it is a frightening and dangerous beast.

A crocodilian creature that is most at home in the warmer waters of Sector Zero. Its intimidating appearance belies a surprisingly cowardly nature.
  • Attack! Attack... Retreat! Retreat!: The Cryptosuchus is incredibly aggressive, going after any prey in its vicinity with reckless abandon. However, if the target fights back in any way, it will turn tail and swim away.
  • Minor Injury Overreaction: Even one hit from a dinky little Survival Knife is enough to send it packing.

    Frozen Leviathan WARNING-SPOILER ALERT! 
A frozen leviathan-class organism found in the Phi Excavation Site. Following the birth of the Sea Emperor Leviathan Juveniles, it is the last repository of the Kharaa Bacterium on Planet 4546B.
  • And I Must Scream: While it is by all appearances dead and referred to as such by the PDA, injecting its corpse with the Kharaa cure purges the entire creature of the infection, even though this would only be possible if its circulatory system was still functioning and pumping blood through its body. Note that there is not indication Alterra did anything to mess with its circulatory system....
  • Foil: To the Sea Dragon Leviathan mother - both are leviathans connected to the Kharaa Bacterium, with virtually all of the bad events of the plot being connected to them. This is where the similarities end, though. The mother Sea Dragon ended up causing the outbreak via intentionally destroying the Disease Research Facility in order to rescue her eggs, and ended up dying due to attacking the Disease Research Facility. The Frozen Leviathan, meanwhile, just had the bad luck to be frozen while infected with the bacterium, which Alterra now wants to study for various medical benefits. There's also a Fire/Water Juxtaposition with the two, as the Sea Dragon is a fully aquatic reptilian predator that shoots fireballs and dwells within an inactive volcano while the Frozen Leviathan is a semiaquatic amphibian predator that is found frozen in ice.
  • Kaiju: It's a leviathan class organism, but unlike the other members of that group, it appears to have been capable of moving both on land and in the water.
  • Kill It with Ice: The posture it was in when it died implies it was apparently flash frozen.
  • Macguffin: It's corpse contains the final surviving samples of the Kharaa Bacterium, which Alterra wants to study.
  • Posthumous Character: It has been dead for a long time, but Alterra's efforts to study it drive the entire plot of Below Zero.
  • Reptiles Are Abhorrent: A Downplayed amphibian example, but this thing has Scary Teeth, tusks, claws, armor, and eyes that all make it look rather intimidating. It also carries the Kharaa Bacterium within it, but fortunately this is the only repository of the disease still left on the Planet.....making it a prized research specimen for Alterra.
    Glow Whale

A massive herbivore native to the Arctic Mega Biome.

  • Gentle Giant: Is the polar equivalent of the Reefback, being a Leviathan-class organism that is completely harmless to the player.

    Ice Worm

Think you're safe from leviathans by staying on the land/ice? Think again, because this titanic creature calls those areas its home.

  • Dynamic Entry: In several terrifying ways. It can burst just its head out of the ice and snap its jaws closed around you if it happens to do it beneath you, if not then directly in front of you. It can erupt completely out of the ice with its leaping attack. It can rise up and give a loud ear-piercing shriek then attack you by either trying to spear you with its horn or doing a half-circle slash with it. And it can charge straight for you under the ice then explode out directly under you and send you flying up into the air then back down right into its open mouth.note 
  • Playing with Fire: Its massive horn/blade snout reaches very high temperatures, allowing it to melt the ice and move through the tunnel with its rows of spines.
  • One-Hit Kill: If it manages to hit you with any attack aside from the half-circle swipe, it will devour you whole with one bite. How you watch yourself be munched depends on which attack it made.
  • Sand Worm: It's enormous, it burrows through the ice like sand, it can detect your footsteps, and it's quick to attack.
  • Shout-Out: The devs admitted that it's a blatant shout-out to Dune, right down to using a Thumper to distract it.
  • Worm Sign: It has this now, creating and leaving a ridge of cracked ice and steam bursts from its horn melting and vaporizing the ice below. It also leaves them in two ways: one that's slow and relaxed as it travels around; and one that's incredibly fast and comes straight at you if it starts charging your location after detecting you.


Jellyfish tend to congregate in groups in the freezing depths of Sector Zero. Unfortunately, these groups are often in the way of Alterra submersibles, making certain routes difficult to navigate.

  • Aerith and Bob: Planet 4546B is loaded with creatures with fantastical sounding names... and this creature is simply named Jellyfish.
  • Eyes Do Not Belong There: The Jellyfish has one eye within it's bell. If the player gets close enough, it'll turn to look at you.

    Lily Paddler

A creature that makes its home in the Lilypad Islands.

  • Interface Screw: Like the Mesmer, this creature can hypnotize the player with their bioluminesence. Unlike the Mesmer, it uses this power defensively, causing the player to lose their bearings while the Lily Paddler swims away.
  • Mix-and-Match Critters: Looks a lot like a weedy sea dragon.


An alien penguin found all over the ice.

  • Everything's Better with Penguins: They're alien penguins, and while the adults will attack you if you strike first, the babies wouldn't hurt a fly.
  • Vagina Dentata: Their beaks take up the entire front of their face, with their eyes alongside them. These beaks open parallel to their line between their belly and back, rather than perpendicular like terrestrial birds.


A creature that fills a similar role to seals on Earth, the Pinnacarid is a friendly creature.

  • Huge Rider, Tiny Mount: They come up to about Robin's hip, and the player can ride on their backs.
  • Sweet Seal: They may not look it, but the Pinnacarid acts very much like a seal.
  • Tastes Like Friendship: The Pinnacarid will sometimes swim up to the player, hoping for a meal.
  • Vocal Dissonance: Those threatening roars you hear in the starting biomes? That's these guys.

    Rock Puncher
A lobster-like creature with huge powerful front limbs. It was originally going to work with the terraforming ability, destroying rocks and digging burrows, but with terraforming being removed it was delayed until the Below Zero update.
  • Giant Enemy Crab: Its a little taller than the player but very bulky and thick.
  • Good Old Fisticuffs: Its front pair of limbs are thick powerful arms ending in spike-covered clubs of chitin that it can lash out with at lightning speed to deter predators and the player.
  • Stone Wall: Despite their small size, the data readout shows that its shell is so tough, only Leviathan-class beasts pose any threat.

    Sea Monkey

A medium-sized sea creature, the Sea Monkey takes great interest in the tools Alterra uses while on Planet 4546B.

  • Helpful Mook: Their nests in the Arctic Kelp Caves can contain fragments that will be useful to the player, provided they can be reached. Additionally, sometimes they will swim up to the player with some ore in it's hands, allowing the player to take it.
  • Ridiculously Cute Critter: Annoying as their kleptomaniac behaviour may be, they do look rather cute. Especially when you take some ore they can present to you.
  • Sticky Fingers: Be careful with your tools around these guys. They like to grab them out of your hands.

    Shadow Leviathan

A massive polar predator, equivalent to the Ghost and Sea Dragon Leviathans in many aspects. At the moment its only hunting ground is the crystal cavern.

  • Dark Is Evil: Not evil per se, but it is mostly a dark gray/black color and is a leviathan-class predator.
  • One-Hit Kill: If it grabs you, you're Swallowed Whole, no matter your health.
  • Sea Monster: It's the polar version of the Sea Dragon Leviathan. Nothing else needs to be said.
  • Slippery as an Eel: Its body resembles that of the knifefish, with single dorsal and ventral fins that extend along most of its body.
  • Super-Persistent Predator: It's aggressive even for a leviathan, with a larger aggro radius than normal, and it moves frighteningly fast in pursuit of prey. Better hope your turbo jets don't fail you when you try to outrace it.


A relative of the Stalker from the Crater, the Snowstalker is a mainly-terrestrial predator that inhabits the ice floes.

  • Bears Are Bad News: Its overall design and habits are based on the polar bear, and it even have bear-like animations such as its run cycle, swiping with a paw to attack, and standing on its hind legs to both see better and attack with a bear hug.
  • Bioluminescence Is Cool: The tip of its tail, markings under its eyes, and tongue glow with a bright cyan light.
  • Cub Cues Protective Parent: Interacting with the juvenile Snowstalker will likely result in Momma Snowstalker coming for you.
  • Finishing Move: If the player's health is low enough, the snowstalker will pin them to the ground, straddle their prone body, and take two swipes at the chest, before finishing them off with a bite to the head.
  • Light Is Not Good: Its fur is white with slightly darker stripes, and it's a dangerous and persistent predator.
  • Never Smile at a Crocodile: Like the Stalker it has a crocodilian head, though its snout is shorter and wider like a crocodile's as opposed to the stalker's long thin gharial-like snout.
  • Ridiculously Cute Critter: The juvenile Snowstalker looks incredibly cuddly, and the player can even feed them and give them a pat. Just mind their teeth.
  • Weakened by the Light: As of the Frostbite Update, adult Snowstalkers will retreat when the player holds up a flare.

    Spike Trap

A creature that makes it's home in the Deep Twisty Bridges. Like the Rock Puncher, it was intended to be in the original Subnautica, but was cut.

  • Planimal: There's elements of both plant and animal in it's design. It was originally classified as flora, but upon it's addition to Below Zero, it was reclassified as fauna.


A large deep-water predator that stalks the Deep Twisty Bridges biome.

  • EMP: The Squidshark uses the glowing tentacles on its underbelly to disable the player's vehicles, much like the Crabsquid's EMP attack.
  • Nested Mouths: When it attacks, it opens the flaps on its face and extends a spike-tooth-lined mouthpart to seize prey by either spearing it with the teeth or catching them in an interlocking tooth cage and drawing them into its throat.
  • Swallowed Whole: If it grabs you when you're above 40 health, Robin will hold onto the teeth then kick at its inner mouth to make it leg go of her. If you're at 40 health or less, Robin is unable to muster the strength for a kick and you get to watch yourself be pulled into its throat.
  • Threatening Shark: In behavior and somewhat body design.


An aggressive predator, the Symbiote lives in harmony with the Titan Holefish. Anything else is chow.

  • Piranha Problem: They live in swarms, and their bites hurt.
  • The Symbiote: It has a symbiotic relationship with the Titan Holefish. The symbiote lays its eggs in the Titan Holefish's gills, and protects them from predators.

    Titan Holefish

A creature that coexists alongside the Symbiote.

  • Helpful Mook: If you can get past the Symbiotes, the holes in their bodies can give you some oxygen. It's a matter of whether it's worth braving the swarm for the extra air.


An absolutely gigantic creature that anchors itself over thermal vents and collects the nutrient-rich water to nourish the ecosystem living inside its body. There are two in the game at the moment, both permanently anchored above a vent, with one being the titanic exmaple and the other being enormous but not nearly as large. There are also much smaller juvenile Ventgardens that float around the same area where the adult two are located.

  • Gentle Giant: Despite its truly gargantuan size, it is a completely non-aggressive creature that feeds on the nutrients being emitted from undersea vents.
  • Kaiju: This thing is enormous, the second-largest creature in the games at 110 meters in height, surpassed only be the adult Sea Emperor.
  • Token Good Teammate: Along with the Sea Emperor Leviathan, the Ventgarden is one of the very few non-hostile Leviathan-class entities.
  • Turtle Island: Played with in that it's underwater, and a jellyfish instead of a turtle, but it still fits the spirit of this trope; the dome on its back contains an entire ecosystem.


Warning: Major story spoilers below.
    The Architects 
A sapient race of mysterious creatures who deployed a crew to Planet 4546B. They shot down the Aurora and Degasi, and later the Sunbeam as well just as it was about to pick you up from the planet.

They currently have four bases on the planet: the Quarantine Enforcement Platform, an installation on the Mountain Island predominantly consisting of a large ground-to-air weapon system designed to destroy large airborne/orbiting targets such as ships and facilitates active primary operations; the Disease Research Facility in the Lost River, used for biotech research; the Alien Thermal Plant in the Lava Castle of the Inactive Lava Zone, which is their main power source; and the Primary Containment Facility in the Lava Lakes, which houses the last living Sea Emperor Leviathan Specimen. There are also a total of ten caches dotted around the Crater, containing either arch-shaped warpgates, sanctuaries and even a field lab.

One thousand years ago, the Architects came to the planet, looking to cure the Kharaa bacterium. In the process, they studied the planet's indigenous fauna (and even tried to crack the mystery of the skeleton in the Lost River, but to no avail), and built the four bases we see now in the event of an outbreak of the Kharaa, designed to quarantine the planet and keep said quarantine in effect even if the Precursors must leave. They also built several Caches throughout the playable area, designed to not only store Ion Crystals, but also act as a safehouse where, in the event of the Kharaa escaping, they could engage in Brain Uploading and remain safe for as long as they needed.

Unfortunately, while studying the Lost River skeleton, they took the eggs from a mother Sea Dragon Leviathan and contained them in the Disease Research Center in the Lost River, where the Kharaa was primarily being researched. Said mother Sea Dragon attacked the facility to recover her eggs and released the Kharaa bacterium onto the planet, leading to mass extinction, and forcing the quarantine on the planet. Flash-forward at least several hundred years later, and the player arrives onto Planet 4546B, who is left to fix what the Precursors started to get off the planet. He does.

  • Ancient Astronauts: One of the many display cases within the Primary Containment Facility contains a fancy sword of human origin, while another holds a non-Earth artifact that suspiciously resembles the Yin-Yang symbol. While the former proves they at least visited Earth centuries ago, the latter implies they actively influenced human cultural development to some degree (although the PDA also posits an alternative theory of the Yin-Yang philosophy being a universal concept that's shared by more or less all civilizations in the universe).
  • Benevolent Precursors: Downplayed. They might have been willing to go to great lengths to try and cure the Kharaa bacterium infestation on Planet 4546B, but they were responsible for introducing the bacterium to planet in the first place, testing it on harmless animals, and kidnapping 315 different leviathans (including the Sea Emperor) to try and find a cure. And they're not even the real villains!
  • Brain Uploading: None of the crew deployed to Planet 4546B actually died. Instead, they uploaded themselves to a safe house in the Blood Kelp Zone, and inhabit the room's walls and machinery. And no, taking their Ion Crystals does not kill them.
  • Bizarre Alien Biology:
    • Data files obtained from their sanctuaries suggest that, in addition to lifespans measured in centuries, the Precursors are grown from "seeds". note 
    • Also a bit of Fridge Logic since the Precursors as a race are so far removed from other life forms on 4546B it's possible they couldn't grasp the concept behind the egg-hatching conditions for the Sea Emperor's babies, despite all the studies they did.
    • Below Zero reveals that they look like Centaurs, have no recognizable face or sensor organs except for arms, and can assemble their bodies in organic factories.
  • Didn't Think This Through: It's pretty clear that the Architects didn't consider the fact that eggs were meant to hatch in an environment built for the babies, not the adult. Not only that, when they took the Sea Dragon Leviathan's eggs, apparently they never considered that the mother would be angry at them.
    • The former is particularly egregious, seeing how this trait is also exhibited by the Ghost Leviathan, and can be observed while travelling down to the Disease Research Facility if you take the right pathnote .
  • Greater-Scope Villain: Despite being long gone, they are unintentionally responsible for most of the main plot. They brought the Kharaa to the planet and their attempts to cure it meant that the Sea Emperor couldn't lay its eggs in the proper environment for them to hatch, forcing it to stay alive way beyond its normal lifespan. Their research of the planet's organisms caused the Sea Dragon to destroy their base to save its eggs, releasing the Kharaa to the general population of the planet. Their attempts to quarantine the planet resulted in the deadly Warpers attacking various creatures on the planet (including the player), along with the Degasi, Aurora, and Sunbeam being shot down, stranding the player.
  • Large and in Charge: Their lab equipment shows that they're quite tall for what they were doing.
  • Not So Different: Their abilities, intelligence and creations match the kinds humans have and can accomplish, at least in Subnautica's universe. Especially played straight when the player discovers that they're rather frugal on power despite using a gigantic volcanic formation in a place already filled to the brim with lava as their power source. There are also models for lab equipment that look exactly like the ones humans use, only more cubic and taller (which implies that they're very tall.) They're also likely to be bipedal.
  • Omniscient Morality License: They've committed genocide of both humans and native species AND forced the remaining Sea Emperor to breed because by doing so, they can free the planet of The Plague that infects it. It works out for both them and the player in the end as the Emperor's eggs finally hatch and accelerate cure production to a much-desired level and using their tech, the player gets off the planet.
  • Our Centaurs Are Different: Below Zero reveals that their true forms look very similar to centaurs, albeit with horns and no recognizable faces.
  • Precursors: They were on Planet 4546B before humans arrived there.
  • Telepathic Spacemen: Inverted Trope. Despite their advanced technology, the Architects were completely deaf to the Sea Emperor's telepathy (unlike even humans, who are not telepathic but able to receive her messages), leading them to attempt to acquire the cure to the Kharaa bacterium through force and her to withhold it in turn. They also failed to comprehend that the reason her eggs were not hatching was that they were being kept in an environment suitable for an adult Sea Emperor, rather than for a hatchling, something she's easily able to explain to Ryley.
  • Volcano Lair: The Primary Containment Facility, which houses the Sea Emperor. To a lesser extent, the Alien Thermal Plant in the Lava Castle and the bio-research facility in the Lost River count as well. The latter was built near the entrance to the Lava Zones from the Lost River.
  • Well-Intentioned Extremist: Most of their more amoral actions were caused by desperation to cure and contain Kharaa by any means necessary rather than malice. They did end up doing most of the work.
  • Would Hurt a Child: A dissected Sea Emperor Leviathan fetus can be found in the Primary Containment Facility. At least they didn't intentionally kill the fetus; it died as a result of an attempt to forcibly hatch its egg.


How well does it match the trope?

Example of:


Media sources: