The document discusses characteristics of dolphins and whales. It notes that they are gray, big animals with large bodies, two flippers, a fin, and a long nose. They can swim very fast, jump, leap, play with people, catch fish, and communicate with each other. The document also provides more details about blue whales, describing them as the largest animal to ever live, filter feeders that eat plankton and krill. It notes blue whales can be heard from hundreds of kilometers away and live in every ocean, with their only predators being killer whales and humans.