The Mephout was a sentient species that had two sexes: male and female. Male Mephout had libidos that tended to flare in inopportune situations. The RST Model Translator Droids, which were created by the Mephout in the female image, had 1.5-meter-tall humanoid bodies with two four-fingered arms, two legs, a torso with a pair of prominent breasts, and a head with two visual and two audial sensors as well as a vocabulator.
The Mephout originated in the Mephout system, a part of the isolated Wild Space sector known as the Mephout Dominion. The nature of the Mephout males' libidos led to the species delegating all diplomatic positions to the females of the species. Correspondingly, the Mephout designed the RST Model Translator Droids, which were manufactured by the Plintep Cybernetics Corporation, to resemble Mephout females, as well.
RST Model Translator Droids, such as 42-RST (pictured), were created in the image of female Mephout.
The RST model droids carried out nearly all translating duties throughout the Mephout Dominion until the sector's discovery by the Galactic Empire. By that point, in contrast to the RST model droids, the protocol droids available in the wider galaxy were capable of not just translating but also interpreting cultural nuances. This factor, combined with the fact that the RST models had caused numerous problems during important government functions due to being highly susceptible to electromagnetic pulses, led to the rapid replacement of the Mephout-designed translator droids by protocol droids. As an ostensible reward for services rendered by the SoroSuub Corporation cargo pilot Bungo Bung, the Mephout gifted the Sullustan with the RST Model Translator Droid 42-RST; however, in reality, they simply viewed it as a way to dispose of a droid that had become obsolete.
The Mephout were mentioned in the Star Wars: The Roleplaying Game statistics included with the comic story "Bungo n' Rusti Get Carry-Out," which was authored by Jim Anderson and published in the November 1996 eleventh issue of West End Games' Star Wars Adventure Journal.