Ser Ilyn Payne is a character in G.R.R.M'S ASoIaF series who wears rusty armor and lives in filthy digs. The only thing he keeps clean is his sword.
He is the King's Justice, a fancy job title for jailer and executioner.
He does not talk because his tongue was ordered torn out by The Mad King when he said something that annoyed the king. This happened before the events in the books begin.
In a story full of many interesting characters he is a minor one who should be forgotten. However, he attracts attention because he beheads Ned Stark on Joffrey Baratheon's orders. This action secures him a place on Arya Stark's hit list and he is kept in the reader's consciousness by Arya's periodic recitation of the list. Another reason for his prominence is that Jaime Lannister's attempts to learn how to fight left-handed involve him. Jaime chooses him as a sparring partner because he (Ilyn) cannot talk, nor write. Thus, he could not inform anyone about Jaime's inability. Further, Jaime thinks his silence makes him the ideal drinking partner since "He never interrupted, never disagreed, never complained or asked for favors or told long pointless stories. All he did was drink and listen."
He scares many of the people in the books not only because of what he does but also because of how he looks. He is described as tall and cadaverous with hollow eyes that, along with his silence, unnerve people. He is not an admirable character. Despite this, I think he has a rather simple life and his job would be a pretty easy gig.