Sperm whale . Myoglobin, which stores oxygen in muscle tissue, is much more abundant than in terrestrial animals. The blood has a high density of red blood cells, which contain oxygen-carrying haemoglobin. The oxygenated blood can be directed towards only the brain and other essential organs when oxygen levels deplete. The spermaceti organ may also play a role by adjusting buoyancy (see below). The arterial retia mirabilia are extraordinarily well-developed. The complex arterial retia mirabilia of the sperm whale are more extensive and larger than those of any other cetacean. Atop the whale's skull is positioned a large complex of organs filled
Killing of animals by crawling up the target's nose and eating the targets' brain. Most attacks happen in moist areas like ponds or lakes. In the middle is the blowfish ("fugu") that can kill animals with its toxic organs that contain tetrodotoxin. The largest animal killer is the blue whale, which is the largest animal on Earth. The blue whale mostly feeds on krill ("euphausiacea") which is a small, abundant crustacean. Blue whales are almost entirely killed by killer whales and by humans. Chimpanzees wage war against rival groups, killing rival males and eating the baby chimps. Ants also wage warfare on other