The killer whale weighs 3.8-5.5 tons. As the heaviest species of Dolphinidae, adult male killer whales can reach 8 meters long, and the maximum can even reach 9.75 meters, while the average length of females is 7 meters, and the maximum can reach 8.5 meters. Its body is spindle-shaped, its surface is smooth, and there is thick fat under the skin to preserve heat. The color of the body is black and white, the back is painted black, and there are saddle-shaped gray spots behind the fins. There are white spots behind the eyes and white abdomen.

1. Dolphins: Dolphins are a kind of whales and aquatic mammals, which are widely distributed in various oceans and prefer to live in groups and feed on fish and squid. This animal has a spindle-shaped body, smooth and hairless skin surface, is good at jumping and swimming, and has a developed sonar system, relying on echolocation.

2. Sea lions: Sea lions are sea lions of fidopod, mainly distributed in the northern hemisphere, and their size is relatively small, generally less than 2 meters. It is gentle in temperament and usually moves collectively. Although its vision is poor, it is sensitive in hearing and smell, and mainly eats benthic fish and cephalopods.

3. Walrus: Walrus is an animal of the genus Walrus in the family Walrus. It has a large body, thick skin and poor eyesight. It has two long teeth, which are similar to elephants on land. Its feeding habits are miscellaneous, mainly eating lamprey mollusks, also preying on squid, shrimp, crab and worms, and sometimes occasionally swallowing a small amount of young plants in water and organic matter sediment on the seabed.