The killer whale (also known as an orca) is a marine mammal and the largest member of the dolphin family. They are found in all the world’s oceans, both cold (Arctic Ocean) and warm (Indian Ocean). Killer whales are social mammals that live in family pods. Their diet varies from fish to marine mammals, depending on where they live. Killer whales are at the top of the food chain, as there is no animal that preys on them.