 Floating , serene aliens known as Engineers , or Huragok , were pulled from Combat Evolved , but made later appearances in the Halo novels . They also appeared in Halo Wars , Halo 3 : ODST , and Halo : Reach . They serve no actual combat role , although in Halo 3 : ODST , Halo Wars and Halo Reach they can aid players or enemies . They are actually artificial lifeforms created by the vanished technologically superior race known as the Forerunners , and are enslaved by the Covenant to build , repair and maintain their technology . 
