Corvo Attano is the protagonist of Dishonored, a stealth action game developed by Arcane Studios. Corvo does communicate inside the game through actions such as killing, hugging, and giving stuff -- but he isn't very talkative.
Even in Dishonored's DLC "The Brigmore Witches", where Corvo appears as an NPC, he does not have a single line. Dishonored's writer has talked about about Corvo's silence before:
I'm biased, of course, but I think Dishonored grips you much more viscerally, more emotionally. And that's on purpose. Corvo doesn't talk and I think it works because everybody knows what Corvo would have to say.