(Alloria's idea, as edited by Simon) A flatted skate-like creature whose body is amde up of three overlapping plates, with each plate being crescent-shaped and having a large spine on each side. They have twelve tiny legs on their underbelly, allowing them to hide themselves in the sand. They are 8m long.
They hide in the sand, leaping up only when prey has been detected in a surprise attack. They are relentless in chasing prey, hpowever not terribly fast. They are the natural predator of the Tiny Fish.
They are cathemeral and spawn mainly in the Seagrass Plains.
Small, swarm-based predators of whom are only half-a-meter long. They resemble tadpoles, however with large, side-mounted fins and small mouths with massive, needle-like teeth that are too large for them to even close their mouth. Additionally, they have multiple spines along both their back and underbelly, with their tadpole-like tail being stretched between the spines.
They swim in large shoals, relentlessly attacking whatever is closest. They are known for suicide-like tactics, overwhelming their prey in sheer numbers alone.
They are cathemeral and can spawn in any biome in/above the Upper Bathyspelagic zone.
Small millipede-like animals with a leech-like face. They
It simply floats with the current, mostly incapable of self-propelled movement. However, if prey is near, it can undulate its body in their general direction, where it will latch onto them using its legs and suck their blood. If they successfully kill something, they will continue to suck on it.
They are cathemeral and can spawn in any biome, usually in groups of 4-5.
A 330+ meter-long creature (largest in the game) with a mermaid-esque body plan. It has a dragon-esque head, with both sharpened teeth and baleen. Its forelimbs resemble sea turtle limbs.
It both feeds on plankton and large creatures. While it has little care for the player alone, it is very curious about Submarines and frequently "plays" with them.
It is cathemeral and can spawn in any biome, however is rare.
A 110 meter-long creature resembling a black dragonfish to some degree. It is black, and slightly translucent. It has two large, membranous side-mounted fins.
It is cathemeral and can spawn in any biome in/below the Main Mesopelagic Zone.
It's an 8m-long eel, though with a semi-transparent fin going along the length of its entire body on each side. It has six antennae on its head, arranged in a row with the taller ones in the centre. Each is topped with a bioluminescent lure. It also features bioluminescent spines on its back.
It is nocturnal and can spawn in any biome in/below the Upper Mesopelagic.