Kenneth "Kenny" McCormick is voiced by Matt Stone (and, on one occasion, Mike Judge) and is well-known for almost always wearing his orange parka, and for being killed in nearly every episode.
Since his hood covers his mouth in all but a few scenes in the show's history, his lines are muffled, though occasionally they are intelligible, and closed captioning sometimes clarifies his lines.
Voice
Kenny's un-muffled voice sounds like a slightly higher-pitched version of Stan Marsh. In the movie Kenny's voice was performed by Mike Judge, creator of Beavis and Butt-head and King of the Hill. In the Season 8 episode The Jeffersons, Kenny's voice was performed by Matt Stone.
Family
Kenny's family is extremely poor. His father, Stuart McCormick, is an alcoholic, and his friends (especially Eric Cartman) often tease him about it. Kenny has two siblings: Kevin McCormick, and a little girl who seemingly has no name. In spite of his poverty-stricken background, Kenny is often portrayed as the hero of the group; indeed, several of his deaths have been acts of heroic self-sacrifice.
Visual appearance
Kenny almost always wears an orange hooded parka with brown gloves (although he does remove it during the movie South Park: Bigger, Longer & Uncut and in episodes 504 "Super Best Friends", 402 "The Tooth Fairy Tats 2000" , 706 "Lil' Crime Stoppers", 807 "The Jeffersons" and 905 "The Losing Edge".). Underneath his hood he has messy blonde hair, which looks very similar to that of another South Park character, Tweek.
Death
Kenny is most famous for dying in nearly every episode of the first five seasons, often followed by a cry of "Oh my God, They killed Kenny!" and "You bastard!" from his friends Stan and Kyle. In earlier seasons rats show up immediately following his death and start nibbling on his carcass. In The Succubus, Kenny even dies twice: first when the boys are waiting for Chef to come play baseball, then the next day when he is squashed by the Succubus during Chef's wedding.
Matt Stone and Trey Parker tried to kill Kenny off completely for a year (he died in the "Hell's Pass Hospital" of an ambiguous muscle disease) and replaced him first with Butters and then Tweek. During the 2002 Christmas episode Kenny returned after being trapped inside Cartman.
Kenny's frequent deaths may be inspired by the Irish county Kilkenny (kill Kenny), as Kenny himself is presumably Irish (this is furthered by his last name 'McCormick', which is of Irish origin).
