An individual of the Balmera species located in the Javeeno star system and subjugated by the Galra in order to mine the valuable crystals it produced. It was eventually freed thanks to Team Voltron's efforts, but left near death after the removal of so much of its life force. Allura was able to revitalize and save the great creature by performing an ancient Altean energy ritual to infuse it with Quintessence.
At the end of Season 7, Balmera X-95-Vox is relocated to Earth's solar system after Earth becomes the new capital of the Voltron Coalition.
The Galra, in their quest to obtain quintessence, used the Balmeran crystals to extract the substance. Balmera X - 95 - Vox is one of those Balmera. The Galra mined deep into the surface of the Balmera and subjugated the Balmerans into their service.