Zorg

 (or  Zostrathnia Otocr Regus Gelb) was an alien friend of the Seventh Doctor. It look like a cross between a jellyfish and a crab. Whenever it said names or titles, it would make the first letter be a Z. Thus, it called the Doctor "Zoctor" and Ace "Zace". He helped retrieve the TARDIS from Lamy, where the Doctor had left it out of concern for the military presence in Los Alamos. (PROSE: Atom Bomb Blues)