Only killer whales are appropriately classified as orcas, and killer whales are actually considered dolphins. The orca, or killer whale, is the dolphin group's biggest mammal.
Mature orcas can weigh as much as 12,000 pounds and grow to be over 30 feet long, and baby orcas can weigh in excess of 350 pounds. Their given name, killer whale, is no misnomer, as these mammals are skilled hunters. Killer whales can travel at speeds in excess of 30 mph, and they are equipped with imposing teeth, which can reach up to 4 inches in length. Killer whales are found virtually all over the world, and they are known to travel great distances amounting to over 1,000 miles.