9. Tom Sawyer
20th Century FoxWe already have our link to the States in the character of Ethan Chandler, so why not introduce Sawyer as an old comrade of Ethan's? We're thinking along the lines of the Tom Sawyer we saw in League Of Extraordinary Gentleman, grown up and out to experience his share of adventure. This personality that Chandler projects to everyone and most of his character arc deals with the fact that those closest to him see through it and realise he's more complicated underneath. Introducing Sawyer as the man Ethan wishes he was could be an interesting dynamic, as well as seeing how Sawyer's more than likely gung ho attitude would be affected by Penny Dreadful's nightmarish Victorian London. Sawyer would have to be a blue eyed square jawed all-American boy, so we're thinking Supernatural's Jared Padalecki would be perfect for the combination of confidence and naivety we'd want for this incarnation.