Gnullith
this star-shaped creature was genetically altered by the Yuuzhan Vong to serve as a form of breathing apparatus. When applied to the user's face, the gnullith sealed itself to the skin and extended one of its appendages down the user's throat. This provided a way to pass breathable air into the user's lungs. Two other appendages closed off the user's nose, protecting against intrusion of the foreign atmosphere. The gnullith allowed the Yuuzhan Vong to travel underwater and in toxic environments without pause. The New Republic's military forces discovered that a warrior wearing a gnullith could be killed if a shot was placed in the very center of the gnullith's body.