The Elth of Balhoon was the Moxx of Balhoon's brother.
Biography
He believed that the survivors of Platform One hadn't tried to help the Moxx and had abandoned him to die, and decided to kidnap them, using his "bioslaves" and take his revenge. The Tenth Doctor and Rose Tyler discovered his plan and rescued his prisoners. The Doctor convinced the Elth that they had done all they could to save him but it was too late. The prisoners not only forgave the Elth for kidnapping them, but they offered to help him. (COMIC: Reunion of Fear)