Elvreng was the second moon that orbited the planet Romulus.

It was regarded by Romulan superstition to be ominous with old tales telling that the position and shape of it in the night sky of a Romulan birth determining whether the child was lucky or unlucky in their lives. An eclipse of sister moon Pirek by Elvreng was considered to be the worst possible omen for a child by superstitous belief. (Last Unicorn RPG module: The Way of D'era: The Romulan Star Empire)