One distinguishing characteristic was their gill-like structures that extended from the bottom of their ears down the ridge of their jaws. They also had a single small ridge on the top of their noses and an olive skin complexion. The Kraylor were unfamiliar with the rank and term of ensign. (VOY: "Nightingale") Several Kraylor were employed at the Primary Energy Facility on Quarra. (VOY: "Workforce") These Kraylor only appeared in the background, such as the large facility room where Captain Janeway worked, so it was not mentioned whether or not the Kraylor were kidnapped.