Calaxi

The Calaxi were a species of blue-skinned humanoids who originated on the planet Malleon.

One day, their homeworld was invaded by the Spherions, a species of inorganic crystals who saw the organic forms of the Calaxi as ideal incubators for their young. The Calaxi attempted to fight back but were ultimately forced to flee across the galaxy. The Spherions destroyed each world they colonised, until one of their leaders, Lumin, discovered a hollow planet, and the Calaxi took residence there, calling it Lumin's World.

The Spherions caught up to the Calaxi at Lumin's World when the Eighth Doctor and Josie Day arrived at the planet, the two travellers managing to convince the Spherions that organic life could be sentient. The Doctor then took the Spherions to a new planet, leaving the Calaxi in peace. (COMIC: Music of the Spherions)