Gelth ambassador

The Gelth Ambassador was the leader of the Gelth, who represented them to the Doctor, Rose Tyler, Charles Dickens, Gwyneth and Gabriel Sneed. It convinced them that the Gelth were dying and they helped the Gelth through to Earth, then revealed they planned to destroy Humanity. The Ambassador was later killed when Gwyneth blew up the building. (DW: The Unquiet Dead)