Moby Dick is a sperm whale who is the main antagonist in Herman Melville's 1851 novel of the same name. Melville based the whale partially on a real albino whale of that period called Mocha Dick. Ishmael describes Moby Dick as having two prominent white areas around "a peculiar snow-white wrinkled forehead, and a high, pyramidical white hump", the rest of his body being of stripes and patches between white and gray. The animal's exact dimensions are never given, but the novel claims that the largest sperm whales can reach a length of 90 ft (larger than any officially recorded sperm whale) and that Moby Dick is possibly the largest sperm whale that ever lived. Ahab tells the crew that the whale can be spotted because he has an unusual spout, a deformed jaw, three punctures in his right fluke, and several harpoons embedded in his side from unsuccessful hunts.

Source: Wikipedia