The nemesis of Vash in the manga and anime "Trigun". As an independent Plant, a normally-passive lifeform used as a sort of power supply (and much more), he sees the ugliness in people as a child and learns to hate them. His brother Vash, on the other hand, continues to care for humans despite their flaws. This disagreement eventually turns them into bitter enemies and forms the basis for the plot of the story.
Knives and Muro seem to have hatred of humanity in common, as they are both physically, if not also mentally, superior to humans (Knives much more so than Muro, but still). Knives is on a mission to eradicate humans from planet Gunsmoke. Muro is consistently depicted as misanthropic, and at the end of Chapter 14, tells Konoko that she will join the others, "choking on dead air and foul water". It seems that he wants to exterminate at least most of humankind, if not all.