The Mustafarian species can't be chosen as a vendor species by a trader.
Star Wars LoreEdit
From the OS Databank.
Despite the planet's extreme conditions, Mustafar has spawned a number of native life-forms. Some of these have even evolved sentience. The native Mustafarians care little about the offworlder concerns on their planet. They simply busy themselves harvesting the minerals carried in the lava streams of their world. There are two notable subspecies among the Mustafarians. Tall, thin ones are known to ride the lava fleas on the cooled, crusted-over surface of lava flows; shorter, burly Mustafarians can be seen riding hovering harvesting platforms, skimming the lava rivers with heavy pole-mounted cauldrons.
Evolved from extremophile arthropods with very little water in their biology, the Mustafarians dwell in the cooler hollows of dormant volcanic mountains. They ventured to the surface world, following a trail blazed by the native lava fleas. Recycling discarded flea shells as armor, the various Mustafarian colonies made contact with one another. They stitched together a loose collection of townships through peaceful trade, banding together in the face of their planet's unforgiving elements.
The northern Mustafarians are the thinner of the two main subspecies. The squatter southern Mustafarians can withstand greater temperatures than their meeker cousins. When the Techno Union arrived on the planet, the Mustafarians signed a treaty with the offworld developers. This galactic trade gave the Mustafarians advanced technology to help resist the fiery dangers of their world.
Mustafarians speak a buzzing, insectoid language. They are very hardy. Mustafarians don't bother with standard laser weaponry, as their skin and armor can withstand the heat radiated by most common blasters. They instead carry a type of native blaster that emits bolts of kinetic force.