Mister Fantastic originally created H.E.R.B.I.E. with the help of Master Xar of the Xandarians, using their living computer technology, to speed up calculations when he was away from the Baxter Building’s computers. Reed Richards continued to use H.E.R.B.I.E.’s abilities although the robot often displayed mysterious signs of autonomy. While the rest of the Fantastic Four were fooled, the Thing continued to distrust the robot, expecting it to talk back to him as it did on their cartoon show.
But H.E.R.B.I.E. soon attacked the FF starting with the Invisible Woman. He revealed that he was actually the consciousness of Doctor Sun who had downloaded himself into the robot at the time of its creation from the Xandarian computers. After subduing most of the four, Doctor Sun uploaded himself into the Baxter Building’s computers to gain more power. Reed shut down the building’s systems to stop Doctor Sun, and having been freed from the villain’s influence, H.E.R.B.I.E. saved them all and cut off Sun’s last refuge by rocketing himself into the building’s computers, destroying himself and Sun.
Since, Reed Richards has used H.E.R.B.I.E.’s appearance and design in further robots and, most notably, as the face and voice of the new Baxter Building’s computer system.