The Silurians arent really considered a monster anymore which is fair enough. Their series five debut established them as some form of threat, but that was neutered once the 1000-year sleep was initiated. The Silurians function as a docile race in a similar vein to the Ood, and they function that way rather effectively. Like the Ood, they can easily be made into a threat if the story warrants it the Oods mind becomes addled and their eyes glow red, whereas a Silurian who doesnt agree with the majority could be introduced to wreak some carnage. But for the most part the Silurians can be seen as good. Should a vicious Silurian story occur, their cousins who first appeared 40 years prior in Doctor Who and the Silurians could easily make a return without taking anything away from the 2010 redesign of the Homo Reptilia. What we do want to see however is a story set 1000 years after 2010s Cold Blood to show what became of the Silurians after their long nap. It would be a stunning episode in which we would see the Silurians living side-by-side with humanity. Whats more, Nasreen, Tony and Eldane could also return to form some continuity between the two episodes. Sounds good, right? The monster threat could from the Sea Devils, the Silurians sea-faring cousins. Having established themselves peacefully on the surface alongside humanity, the Silurians could invite the Sea Devils to similarly find peace on Earth. But in a similar vein to The Hungry Earth the Sea Devils would react adversely to this new treaty and enact revenge in the hope of retaking Earth from humanity. An all-out war would ensure, before peace ultimately is established. We all want the Sea Devils to return after all.
