Drell
The drell is a lifeform native to Fahz (Beta Aquarii I) that was worn alive by the Utwig as masks during their ancient past, when they realized that the face is the source of all negative aspects of a sentient being. Apparently, the Utwig now find strange the idea of wearing a living creature, as evidenced by the way they phrase the statement "and even living drells were donned in the early days."