Androzani Minor

Androzani Minor was a dry, sandy planet close to Androzani Major. Androzani Minor was a desert planet, its oceans having dried up billions of years ago. Due to the unusual composition of the planet, boiling hot mud flowed throughout the planet's crust, blasting its way to the surface in dangerous explosions. The planet was riddled with caves that had been excavated by the violent mud flows, some of which lacked oxygen.

Despite the conditions of the planet, it had a breathable atmosphere and was home to some forms of life, such as the Spectrox Bats and the Magma Beasts. humans also came to the planet, mainly to gather the Spectrox found in the caves; it did not seem to have any permanent human settlements aboveground (DW: The Caves of Androzani)