Planet:Hydrus

Hydrus is one of the strangest planets in its sector. It has no atmosphere and its surface is completely covered in water. It is the size of a small gas giant, but only has one moon. This moon follows a rare orbit that always takes it between the star and the planet, leaving the planet in a permanent solar eclipse.

The planet's underwater ecosystem is very dense, including millions of different species. Most notable are the squid-like Hydrians, who control the planet but are oblivious to life above the water's surface.