Snoke is the Supreme Leader of the First Order across The Force Awakens (2015) and The Last Jedi (2017), performed by Andy Serkis in motion capture. The Rise of Skywalker (2019) reveals that he was a strand-cast — an artificial being engineered in a laboratory on Exegol — created and operated by Palpatine.
The reveal, and the argument about it
It is worth being straight about the reception. Snoke was built across two films as an enormous unexplained figure, killed abruptly halfway through the second, and then retroactively explained in the third as a tool. Some viewers read that as the trilogy refusing to reward speculation; others read it as three films that never agreed on what he was for. Both readings are defensible and this site is not going to pretend otherwise.
What he actually does in the story
Set the trilogy-level argument aside and there is a functioning character in The Last Jedi. Snoke's role there is to be the voice that tells Kylo Ren exactly what Kylo Ren fears is true — that the helmet is a costume, that the killing did not resolve anything, that he was beaten by an untrained opponent. He is a villain who works by accurate cruelty.
Strand-cast, not clone
The distinction the reference material keeps is worth preserving: a strand-cast is a constructed being grown from manipulated genetic material rather than a copy of an existing person. The Exegol tanks in The Rise of Skywalker hold several Snokes, which is the film's most efficient way of saying he was never the author of anything.
The throne room
His death is the pivot of the trilogy. He spends the scene narrating Kylo Ren's mind with total confidence, states plainly that he cannot be betrayed because he sees every intent, and is bisected by the lightsaber he has been looking at the whole time. The film is making a specific point about how far certainty gets you.
Design
The final creature — asymmetric skull, ruined face, gold robe — was realised entirely as a digital character, and the choice to keep him hologram-scale in The Force Awakens and then reveal him at ordinary human size in The Last Jedi is one of the neater visual jokes in the trilogy.
Canon status
Canon. Snoke has no Legends counterpart; he was created for the sequel trilogy in 2015.
Where to read more
The The Last Jedi novelisation gives the throne-room sequence considerably more interiority than the film has room for, and the Rise of Skywalker novelisation is where the Exegol material is set out most clearly.
