Moby Dick is a fictional white sperm whale, the main antagonist in Herman Melville's 1851 novel Moby-Dick. The whale is based on a real albino sperm whale named Mocha Dick, known in the 19th century for its size, power, and aggressive behavior toward whalers. The fictional Moby Dick is described as having distinctive white areas, including a snow-white wrinkled forehead and a high white hump, with the rest of the body having stripes and patches of white and gray. Melville's Moby Dick is one of the largest sperm whales, possibly larger than any sperm whale recorded in reality. The novel portrays the whale as intelligent and exceptionally ferocious, famously biting off Captain Ahab's leg.