Twin Brother of Vash the Stampede.
full name: Million Knives
wishes to kill humans because they use plants to keep themselves alive. believes that his race (plants, you don't believe me? read the manga) is the most superior ever.
kills legato in the manga, but not in the anime.
Legato: (to the Gung-ho guns, talking about Vash) KILL HIM!!!
Knives: Who said you could kill him?!? YOU PIECE OF TRASH!!!
(then he folds legato in half)