Healii (Taxonomically Horrendus everto; known by humans as Serpents) are a race of semi-aquatic beings, believed to have formed on the Forerunner's Installation 07. They have rarely made contact with other species of the Interstellar Union, but such interactions always lead to violence. Little is known about them, and they clearly do not want the Interstellar Union to "invade" their home territory, or the system housing their Installation.