Space barnacle

Space barnacles were a space borne species that fed off energy and converted it into mass to reproduce. They looked like white ridged domes. Some space barnacles attached themselves to the Godspeed, and started taking its power. They killed Tobbs when he tried to investigate. The Ninth Doctor told the crew to shut down all systems, materialised outside the Godspeed and used the light on top of the TARDIS to attract the barnacles. When they all moved to the TARDIS, he dematerialised, taking the sphere of barnacles with him, and rematerialised in a nearby asteroid belt where the barnacles could feed off the sun. (PROSE: The Hungry Night)