A killer is a violent and psychopathic individual who commits several murders in a short period of time, and may or may not have a “cooling off” period between each murder. Serial killers are often psychopaths who lack empathy and guilt, and have no remorse over their actions. Some kill for money, others for revenge and still other serial killers are driven by a deep psychological thrill or pleasure.

Some of the world’s most notorious and infamous serial killers include Jack the Ripper, who is believed to have killed many women in nineteenth century London, and James Holmes, who murdered twelve people at a movie theater in Aurora, Colorado. They are all different types of criminals, but both had their roots in the slums of nineteenth century London.

The eyes of a killer whale are about the same size as a cow’s, but their eyelids are very thin and they do not have external flaps or pinnae (the small, inconspicuous openings behind the ears). Glands at the inner corners of the eye sockets secrete an oily, jellylike mucus that lubricates the eyes, washes away debris and probably helps streamline the eyes when a killer whale swims.

They also have a single blowhole on top of their head, which is covered by a muscular flap that enables a killer whale to breathe through it in a closed position. When a killer whale is swimming, the blowhole opens and closes rapidly to allow for underwater breathing.

There are five different forms of Antarctic killer whales, each characterized by a slightly different appearance. The largest are the Antarctic type A killer whales, which can reach lengths of 9.2 m (30 ft.). The smallest are the Antarctic type C killer whales, which can reach lengths up to 6.1 m (20 ft.).

These whales have a distinctive white eye patch, a dorsal saddle and a faint cape (a dark gray covering over their back) that is often covered by a layer of diatoms. A killer whale’s skin is very smooth and constantly renews itself by shedding old cells.

Their teeth are large, conical and interlocking, enabling them to eat large amounts of fish. The teeth of some adult offshore killer whales have been found to be worn down, likely due to a diet of krill and sharks that have a highly abrasive skin.

The teeth of a killer whale are also extremely sharp, and are used to cut up the flesh and muscle of small invertebrates and animals. The incisors (front teeth) have a high angle, while the molars are shorter and more pointed. They can also be used to chew on fishes, octopuses and other invertebrates.

Some killer whales are primarily vegetarian, while others eat a variety of marine mammals, including seals and sea lions. They are known to eat as much as 30 kilograms (66 pounds) of food per day, depending on their size and diet.

Some killer whales are solitary or social, while others are family groups that live in packs of up to twenty whales. Some are born and die together. Some killer whales migrate a great deal, while others stay in the same location year-round. They have a wide range of sexual and mating behaviors. They can be very aggressive toward other killer whales and attack them as well as humans.