The Numol'elrul represented a unique subspecies within the broader Nikto lineage. In the distant past, predating the Galactic Civil War, the Numol'elrul chose to withdraw into underwater environments, effectively cutting themselves off from the rest of their kind, which led to their existence being relegated to the realm of legend among other Nikto.
Possessing the ability to respire both in terrestrial and aquatic environments defined the Numol'elrul. Distinguishing themselves from other Nikto subspecies, the Numol (their self-designated name) exhibited scales that were green and blue-green in coloration.