In a parallel universe, Zeuro was a Time Lord who tried to stop the Doctor from interfering with history. He had been sent after the Doctor by that universe's version of Susan, who had become the President of Gallifrey.
He tried to drag the Doctor forcibly back to Gallifrey by linking their TARDISes, but the Doctor managed to break free and was rescued by the Golden Hind.
He was infected by the Angels. (AUDIO: A Storm of Angels)