Orcas, also called killer whales, are actually members of the dolphin family. Orcas hunt in cooperative groups called pods and have distinctive black and white coloring.
Orcas are familiar animals to many people from popular culture and a time period (most of the 20th century) when it was common to keep them in captivity. For many years, it was possible to visit an aquarium and see orcas perform tricks. Movies like "Free Willy" popularized orcas and also helped build opposition to keeping orcas captive. The name orca comes from the Latin name for their genus. Earlier, mythical sea monsters were commonly called orc.