a giant predator based on a giant siphonophore

Siphonophores are really cool predatory organisms that form massive free-moving colonies of single-cell organisms. Different cells specialize in different functions for the colony, making the colony almost function like a complex animal. In real life they can definitely reach Leviathan proportions, reaching well over 100m in length. Adapting that sort of biology into the game world would be really cool.

They’re also visually stunning and quite alien in appearance, usually looking like a cross between a sea serpent and a jellyfish.

A big siphonophore serpent faintly bioluminescing in a deep, dark biome would be absolutely haunting, drifting through the dark water and entangling prey in its thread-like tendrils.