Supreme Leader Snoke, the giant and imposing leader of the First Order was certainly a character not to mess around with in “The Force Awakens.” Kylo Ren was seduced to the dark side of the Force because of him and the First Order does not move without his go-ahead.
However, not much was revealed about his character aside from some hints, especially in the novel that he was very afraid of Luke Skywalker, and he is an ancient character, probably as old as Yoda or another new character, Maz Kanata.
Snoke is certainly a new name in the “Star Wars” universe, but some fans have been putting forward a popular theory that Snoke may actually be based on an already previously existing character from the now defunct canon of the expanded universe from pre-Disney acquisition of LucasArts and the “Star Wars” franchise.
The fan theory that Snoke is actually a new incarnation of the character of Darth Plagueis, the Sith Lord who was master and teacher to Emperor Palpatine and the one who refuses to die. However, Andy Serkis, the actor who played Snoke in “The Force Awakens” via motion capture performance, had put that theory to rest long before the movie even came out in theatres.
According to interviews with the acclaimed actor, Snoke is a fresh, new character created for “The Force Awakens” who doesn't even know what happened in the earlier films.
He also goes on to say that his performance played a big role in conceptualizing the final look for Snoke which was still unclear even as they began filming.
Although many fans have decried the use of CGI for Supreme Leader Snoke's appearances, Serkis defends the decision, saying there was no other way to get the humongous, imposing look they wanted for Snoke with prosthetics. As well, he says the facial design was so extreme that it would have impeded his performance. Therefore, motion capture and CGI was the route taken.
So there goes the theory that Snoke is a reincarnated Darth Plagueis. We'll just have to wait until Episode VIII comes out to learn more about this powerful, evil, and mysterious Supreme Leader.