The Nezu were a humanoid species from the Delta Quadrant that have a ridge running down their face and horns above their eyes. In 2373, Voyager encountered the Nezu after a Nezu colony was hit by a massive meteoroid strike. It was soon discovered by a Nezu physicist, Vatm, that the meteoroid strikes were actually an attack by the Etanians. Vatm was killed before he could reveal this, but his data made it's way to Voyager and was used to drive off the Etanians. (VOY episode: "Rise")