Related: Subnautica: Where to Find Cuddlefish Eggs One of those animals, the Reaper Leviathan, is infamous as being one of the more terrifying creatures in the entire game. Dominated by water, the planet is filled with its own array of plants and animals-some of which are incredibly dangerous. Being set on the mysterious alien planet of 4546B, Subnauticamixes survival elements with exploration as players set out to discover why their ship crashed.