The Ghost Leviathan is a leviathan class fauna species and adult form of the Ghost Leviathan Juveniles. It is the second largest aggressive creature of Subnautica (the largest being the Sea Dragon Leviathan and the third being the Reaper Leviathan).
If the player enters the Crater Edge, a single adult Ghost Leviathan spawns in. If the player stays in the Crater Edge for thirty seconds, a second Ghost Leviathan will spawn. If the player stays in the area for another thirty seconds, a third and final Ghost Leviathan spawns in. Even if the player somehow kills them, they will respawn. They will all pursue the player until the player returns to the playable area, upon which they will all retreat.
The Giant Cove Tree is the nesting ground of this leviathan species (although they are not present around the tree), with its massive glowing bulbs being their eggs which are blue and purple. According to PDA scan entries of the Cove Tree, the eggs were laid there when the tree was small, and the branches have grown around the eggs to protect them until conditions are right to hatch.
The Ghost Leviathans' life cycle begins in the Lost River as juveniles, they consume the Ghostrays and River Prowlers and potentially other juveniles. As the leviathans mature and become too large for their home, they migrate to the open, surface world biomes such as the Grand Reef and Blood Kelp Zone, consuming Ampeels and Crabsquids in the Northern Blood Kelp, and shoals of fish and possibly even Sea Treader Leviathans in the Grand Reef, until eventually migrating to the Crater Edge, roaming freely in the open water and constantly growing larger until they die. Despite being much smaller than the Sea Emperor Leviathan, the Ghost Leviathan's eggs can be far larger, capable of growing to sizes far too large for the creature to lay, suggesting that the eggs can grow drastically after being laid. Since the Ghost Leviathans in the Crater Edge are able to survive there.
The Ghost Leviathan has a soft, bioluminescent, transparent outer membrane covering a muscular, blue, inner body which features many darker blue stripes, 12 yellow, bioluminescent eyes as well as six, possibly vestigial fins on the torso section. A small sail sits on top of the head, and two long structures protruding from either side of its head which bear similarities to the cephalofoil of a hammerhead shark. It has a rectangular mouth with a glowing barbule lure beneath. Its long body tapers to a point.
The outer body is transparent, making the smaller, inner body visible. The inner body is long and thin, and covered in pulsating, bioluminescent orange stripes with many orange tipped protrusions ending with blinking bioluminescent orange glows. Unlike the outer body, the inner body has a distinct, thin neck joining the head and body. As the leviathan moves through the water, it leaves trails behind it.
To attack a target, it will spiral up and charge. When charging, it will open up its mouth and make a loud, echoing screech. If it successfully attacks, it will do 84% damage to the player and swim some distance away, as if losing interest.
Adults are able to push the Cyclops and either drag it, or overturn it. If the player is walking around the Cyclops when the Adult begins to push (for example, if they are trying to put out fires caused by an attack), and the Leviathan rolls the submarine over, the player can be killed instantly upon colliding with the walls or ceiling. When killed the Ghost Leviathans that are within the Crater do not respawn, however the adults that reside within the Crater Edge will continue to respawn.
Data Bank Entries
This creature is approaching the size limit for sustainable organic lifeforms, and has been designated leviathan class. Adults of the species have been encountered exclusively around the edges of the volcanic crater which supports life on this part of the planet, and react with extreme aggression on approach.
Assessment: Extreme threat - Avoid the crater edge
- The adult Ghost Leviathans found in the void are roughly 1.15x as large as the adults that are found in the crater, given that the entry of Ghost Leviathan Juveniles states that their growth "shows no sign of stopping" it is possible that this species grows continuously throughout their lifespan.