Ko-Dan

The Ko-Dan were a race of humanoid aliens who make up the Ko-Dan Armada. Upper-class Ko-Dan, such as Commander Kril, can best be described as resembling humanoid trees, with skin that resembles the gnarled bark of a tree and lumpy protrusions on their faces (especially their foreheads and chins). They wear large helmets; black for fleet commanders and red for subordinate officers.

Lower-class Ko-Dan are apparently all cyborgs, speaking through voiceboxes in their necks and sitting plugged into Ko-Dan command ships and deck fighters. They all wear helmets with large black goggles over their eyes, and without these helmets they are apparently incapable of survival as demonstrated when Xur knocks one's helmet off, causing him to die.

It is said that the Ko-Dan are ruled by an emperor, but he is never seen nor is his name mentioned by either Xur or Kril.