There's a theory that's been going around online that Snoke is actually Darth Plagueis, the Sith Lord that trained the Emperor.
Serkis told EW.com the following about Snoke:
"Supreme Leader Snoke is quite an enigmatic character, and strangely vulnerable at the same time as being quite powerful,” Serkis says. “Obviously he has a huge agenda. He has suffered a lot of damage. As I said, there is a strange vulnerability to him, which belies his true agenda, I suppose.”
The article goes on to state that Snoke isn't Darth Plagueis, and while Serkis isn't quoted directly as stating it, EW notes:
Although there was much speculation about who Snoke might turn out to be (one popular theory was that he’d turn out to be a Sith Lord known from the prequels as Darth Plagueis) he actually turns out to be … just Snoke.
Serkis said the character was aware of the events from the earlier films but was a new addition to the storyline.
There is just one problem in that it should be noted EW.com is using quotes from an older article from November. So what gives? Is EW just providing spin to steer people in the wrong direction?
Honestly, I'm still not sold on Snoke not being Darth Plagueis - as Serkis didn't specifically deny or say it - but I guess we'll have to wait and see. In additon, the John Williams music scores match up, and reportedly, Disney told a movie podcast to scrap mention of Plagueis.
Another theory has aalso popped up online regarding the look of Snoke, is that he may be blind in one eye. A Redditor manipulated the image, which may hold some truth to it as Snoke's left eye does look blind.