'Doctor Who's Ice Warriors will have ''something new'' about them when they return to the show.The Martian creatures - who debuted on the sci-fi drama in 1967 - have been redesigned for this Saturday's (13.04.13) episode of the BBC show and writer Mark Gatiss promises they have different features to their previous incantation. He said: ''I'd always wanted to set a 'Doctor Who' on a submarine, one day I said [to showrunner Steven Moffat] 'How about an Ice Warrior on a sub?' And there's something else about them, something new. ''The 'something new' got us both excited and so this Saturday's episode, 'Cold War', was born.'' Mark also said the episode pays homage to former Doctor Patrick Troughton, who first fought the Ice Monsters. He added: ''The episode is a love letter to those Patrick Troughton stories that so often saw a group of desperate, frightened people under attack from an alien menace.'' However, Mark did concede The Doctor and his assistant - played by Matt Smith and Jenna Louise Coleman - will have a little more space to manoeuvre than if they were on a real submarine. He explained: ''We had to 'Hollywoodise' the amount of room on board. it would be hard to hide a seven foot monster on a conventional submarine.''