Comment The scariest monster should be the Doctor (Score 1) 170
There are many ways this could be explored; where the Doctor has to do the right thing, which isn't necessarily the good thing. I also wish that the plot line they had in mind for Colin Baker's Doctor could have been done properly, instead of being mangled about by writer's strikes etc. For its time, it was quite revolutionary - the idea that the Doctor's regeneration had gone subtly wrong, leaving him more like the Master than the Doctor. The Sixth Doctor's arc was meant to be a slow descent into hell for the character, and any companions unfortunate enough to get caught up in his self-destruction, before his realisation that it had all gone wrong, and his deliberate suicide, in the hope that the next regeneration would correct the problem, because he was too dangerous to leave running around.
That arc would have made the Sixth Doctor a damaged and tragic figure in the Who mythos, not just the 'bit of a twat' he's generally regarded as, which I feel is a bit unfair to Colin Baker.