Perhaps one of the most memorable one off monsters, the Raston Warrior Robot is described as being one of the most perfect killing machines ever devised. What makes the RWR so terrifying in The Five Doctors is the rapid, fast paced action and utter unbeatability. The speed, stealth and power behind this veritable nightmare in silver make for a truly creepy foe. The fact that the RWR remains so firmly lodged in the collective Whovian consciousness is a testament to the beautiful simplicity of its underrated design. Again, the RWR is one of the few monsters on this list that wouldn't need much of a design update to feel thoroughly modern. This minimalist design would work well when combined with its naturally quick movements to create a sleek and scary creature that would make a brilliant juxtaposition with the slower pace adopted by the Twelfth Doctor. Modern technology could now do the concept and design of the Raston Warrior Robot true justice and make for one of the most impressive monster comebacks of recent years. The ball's in your court, Moffat! What do you think? Did your favourite Classic Series monster make the list? If not, let us know in the comments section below!