Killer whales (虎鲸) belong to toothed whales, who are the largest of the dolphins and king of the sea, biggest carnivore(食肉动物) of the sea, killing all kinds of animals in the sea, even the huge blue whale, like tigers on land, working in a team. 　　Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. Baleen whales are generally larger than toothed whales, and females are larger than males. This group includes the largest known animal species, the Blue Whales.