Quoth

The Quoth were a subatomic sentient species, no larger than a string of quarks. They had the power to alter matter. (PROSE: So Vile a Sin)

They lived at least eighteen thousand times faster than a human. Their original homeworld was a spinning cylinder of neutronium, a light-day long, whose rotation distorted time. When the cylinder was destroyed (PROSE: The Death of Art) by an N-Form, (PROSE: Damaged Goods) the Quoth drifted through space until they encountered Earth. (PROSE: The Death of Art)

There, they found the only source for their birthing materials was inside the human brain, created as a side-effect of psionics. Ironically, the extraction process stimulated the psychic nodes in the host's brain, increasing their psionic ability.

Once freed from Montague's enslavement, the Seventh Doctor took them to a new home, the neutronium remains of a first-generation star at the galactic core. (PROSE: The Death of Art)

Ambassador Galaxy Violet of the Quoth was one of the negotiaters from across the Universe who were present for the signing of the Christmas Needle Agreement. Galaxy Violet briefly encountered Graelyn Scythes. (PROSE: White Canvas)