Made of shadows and thought, immortal, timeless and utterly deadly, Shayde is an absolute must for televised Doctor Who. He was introduced in the Marvel Comics story The Tides of Time in which he helped the Fifth Doctor save all of Creation from the vile demon Melanicus. In later comics, Shayde impersonated the Doctor to confuse the hero's enemies before merging with one of the TIme Lord's companions to avoid death. The gun-toting Shayde was an artificial being who slowly attained full awareness over the course of several stories. Created by the Time Lords, he used technology provided by them and other High Evolutionary species. The extraordinarily advanced systems incorporated into Shayde allowed him to pass easily through TARDIS defences as well as to detach his head and plug it into a computer. His removable head was even shown to be hollow when it shattered, which is the kind of gripping image that looks great on TV. Presumably, the super-advanced species of the Universe could create another Shayde unit to assist the Doctor against a cosmos threatening peril. Creating a new Shayde would allow the Doctor Who production team to have their cake and eat it - they could debut a character with all these amazing abilities without having to mention any back story, other than a quick, "I once met another one of these things - he was a decent chap". Whether the hyper-lethal Shayde could truly be trusted would make for another fascinating element across multiple appearances. And it has to be said, a man with a black goldfish bowl for a head isn't that hard to bring to life on a small screen budget.