Killer whales, also known as orcas, are large marine mammals that can grow up to 32 feet long. They are found in oceans worldwide and eat a varied diet including fish, seals, sea lions, penguins, and other marine animals. Killer whales live in social pods that can range in size from 6 to 40 individuals. Within pods, they work cooperatively to hunt for food and care for young and injured members.