Uth is a perpetually dim world whose brightest days resemble a moonlit night on many inhabited planets. With so little stellar energy, one might assume Uth would be barren, as is the case for many dimly lit worlds where photosynthesis is impossible. Instead, however, the foundation of Uth's ecosystem consists of vast colonies of chemosynthetic organisms that draw energy from the geologically hyperactive planet's volcanic hot springs, fumaroles, and geyser fields. Although often mistaken for plants by outsiders, many of these sedentary organisms are evolutionarily closer to invertebrate animals or fungi, forming forests of fleshy fronds, branching towers, and porous reefs around geothermal vents. True vegetation does exist, but it is comparatively less common, consisting primarily of mycoheterotrophic species that derive nutrients through symbiotic fungal networks. Animal life has adapted accordingly. Bioluminescence is widespread, and many species rely on echolocation, acute senses of smell, electroreception, sensitivity to vibrations, and large reflective eyes to navigate the perpetual twilight. The sapient species of Uth are primarily Uthian Ashan. This mammalian subspecies are gray-skinned and have more reactive eyeshine that glows shades of turquoise in the dark. Until their discovery by early post-Darkening Inferi explorers, the Uthian Ashan had been planet-locked, living among partially restored ancient ruins clustered around reliable sources of fresh water. Following the League's expansion into the Inferi Wing, the Uthian leadership entered into an alliance with the Oono'ad League.