Reefback Leviathan

The Reefback is a life form belonging to the fauna category.

It is massive in size (see comparison with Seamoth in the gallery) and very slow. It appears to patrol the sea mostly in herds of more than two. They appear to be a hybrid between a whale (for their prodigious size and calls) and a Portuguese man o' war (for their purple, humped backs, tails, and strange underbellies).

The Reefback's attitude is passive, and it appears to be cathemeral (active both at night and during the day). It is bioluminescent and emits very audible, low-frequency calls, which are similar to a whale's.

Reefbacks are currently found in the Mushroom Forest and Grassy Plateau biomes.

Speculation
As seen in the concept artwork, it is possible that the Reefback will shelter an entire and unique ecosystem on its back.

The Cyclops submarine can emit a low-frequency noise similar to the Reefback 's calls. In the future, there may be an interaction between the two.