Snoke is Darth Plagueis
The idea that Supreme Leader Snoke is actually Darth Plagueis was one of the earliest theories about the villain’s identity. For a quick refresher, Plagueis was an incredibly powerful Sith Lord who taught the Emperor Palpatine. This is the Sith that found a way to cheat death, and the story that ultimately tempts Anakin to the Dark Side.
The strongest evidence for this theory comes from “The Force Awakens” novelization, where Snoke is described as tall, gaunt, and humanoid. Plagueis was a Muun which is a species that’s also tall, thin and humanoid. Sharp-eared fans have also pointed out that the music played when Plagueis was previously mentioned in “Revenge of the Sith” is eerily similar to Snoke’s theme in “The Force Awakens.”