The Dalby Spook or Gef was a talking mongoose. He knew that Harry Price, the Eighth Doctor, Liv Chenka and Helen Sinclair was coming to see us. He knew extraterrestrial knowledge which proved to the Doctor that he was not a fake. He broke the Doctor's sonic screwdriver. The Doctor captured him in a music box, but Helen realised that he wasn't the enemy but her companion. He was there to protect her from the Sleech. (AUDIO: The Dalby Spook)