Reefback Leviathan

The Reefback is currently the largest passive life form in Subnautica, belonging to the fauna category. It dwells exclusively in the Grassy Plateaus.

Appearance
The Reefback is massive in size, with most of the creature's body being comprised of a thick, purple carapace having a triangular front, and a relatively small body concentrated in the posterior. Attached to its main body are three long whip-like tentacles.

The carapace is patterned with slightly bright blue dotted pattern across towards the back. Beneath its carapace, it is dark green with light blue bioluminescent stripes on the sides and in the middle. On either side of its body are eight yellow bioluminescent bulbs which are believed to be eyes, with two siphon-esque structures seen next to them.

Behavior
The Reefback drifts slowly and gently around the open waters of the Grassy Plateaus, mostly seen swimming in pods of more than two. It almost never adjusts its current altitude, unless bumped against obstacles.

The Reefback's unique trait comes from its ability to emit a wide range of echoing, low-frequency calls.

Gallery
For a more complete gallery, visit Reefback/Gallery.

Speculation
As seen in the concept art, it is possible that Reefbacks will be capable of sheltering an entire ecosystem of coral reefs on its back in a future update.

Trivia

 * The Reefbacks' calls are similar to those of real life whales, which could probably be their way of communication.