The inhabitants of Mixtus II and Mixtus III were a species of humanoids who had purple- or red-colored skin, four webbed fingers – including a thumb – on each hand, and one or two fins on their heads. The vast majority of the species lived on Mixtus III and its seven moons, while Mixtus II was inhabited solely by a single wealthy couple in 2380. Jet Manhaver referred to them as "some purple people."
In that year, the fifth moon of Mixtus III entered a decaying orbit, threatening to collide with the planet and destroy its population. The inhabitants requested aid from the United Federation of Planets, who sent the USS Vancouver and the USS Cerritos to safely demolish the moon. Despite some pushback from communities that venerated, inhabited, or otherwise relied on the moon, a compromise was eventually reached, and the moon was destroyed. Soon thereafter, the resultant lunar debris became a new ring system around Mixtus III. (LD: "Cupid's Errant Arrow")