The Brain Balls are the leaders of the planet Spheron I and the Spheron. Unlike the normal Spheron, they are fully sentient. They appear to have the ability to levitate. There are a known 3 Brain Balls, all of slightly different colorations - Pink Ball, Orange Ball, and Purple Ball. At the end of War is the H-Word, they and the spheron surrender Spheron, their homeplanet, to earth.
They believe in up to seven varaeties of bouncing, their primary means of transportation.