Planet
Ozmarin
The shoreless ocean: not one metre of dry land on the whole planet, colossal creatures in the deep, and islands that are in fact alive.
Ozmarin is entirely covered in water. Not an island, not a rock, not a beach: nothing but ocean, from pole to pole, over a depth no one has managed to measure.
What lives below
The Arazian probes sent into the deeps of Ozmarin all stopped transmitting after a few hours. The recordings they had time to send back show silhouettes kilometres long, passing slowly before the lens without ever fitting entirely into frame. The Empire classified the planet and forbade all descents.
The living islands
Here and there float islands covered in grass and shrubs. They are not islands: they are backs. They breathe once an hour, very slowly, and move a few kilometres a day. Landing on one is not dangerous — except on the day the thing dives, and that does happen.