Motura was the Vidiian whose life depended on the lungs taken from Neelix, forcing Janeway into a hard ethical choice in Phage.
Motura was a Vidiian afflicted by the Phage who worked with Dereth at a cloaked harvesting facility hidden in a planetoid. The two collected organs from other beings to replace their own failing tissue, and Neelix became one of their victims when his lungs were taken during an away mission.
In Phage, Voyager pursued and captured the pair, only to learn that Neelix's lungs had already been transplanted into Motura. Removing them would have killed him, and Janeway refused to take a life even to restore a crewman's. She released the Vidiians, and Dereth then helped save Neelix with a lung donated by Kes.