Killer whales, also known as Orcas, are most common in Arctic and Antarctic waters but are found in every ocean on earth. They are toothed whales, related to sperm and pilot whales, and apex predators vulnerable only to large sharks. The big, beautiful, intelligent killer whales are the true celebrities of the sea, featured in every marine park, and beloved as the stars of several movies including the smash hit Free Willie. They are anything but cuddly, though, and prey on fish, birds, seals, sea lions, squid and even other whales, growing up to 32 feet long and weighing 18,000 pounds. They are threatened by pollution and other human activities in many part of their range.