The Orca or Killer Whale is not a whale, but the largest species of the oceanic dolphin family. They are sometimes referred to as blackfish, a group including pilot whales, pygmy and false killer whales, and melon-headed whales. It is the second-most widely distributed mammal on Earth and is found in all the world's oceans, from the frigid Arctic regions to warm, tropical seas. It is also a versatile predator, eating fish, sea turtles, seabirds, pinnipeds, elasmobranchs, sirenians and even other cetaceans. This puts the orca at the pinnacle of the marine food chain. Orcas have been known to attack baleen whales, in particular gray and Blue whales.
Orcas are magnificent marine mammals, with a fearsome reputation that goes as far back as Pliny the Elder's description of the species. The name "killer whale" reflects the animal's habit of attacking whales, and does not mean that orcas are a threat to humans. Aside from a boy who was charged while swimming in a bay in Alaska, there have been no confirmed attacks on humans in the wild. There have, however, been isolated reports of captive orcas attacking their handlers at marine theme parks.