The great white whale portrayed in Herman Melville’s classic novel Moby Dick was fictitious. But remarkably, it was based on a real animal. An huge albino sperm whale with a violent streak had fascinated whalers and the reading public for decades before Melville published his masterpiece.

The whale,”Mocha Dick,” was named for the island of Mocha, in the Pacific off the coast of Chile. He was often seen in nearby waters, and over the years a number of whalers had tried and failed to kill him.

By some accounts, Mocha Dick had killed more than 30 men, and had attacked and damaged three whaling ships and 14 whaleboats. There were also claims that the white whale had sunk two merchant ships.

There’s no doubt that Herman Melville, who sailed on the whaling ship Acushnet in 1841, would have been quite familiar with the legends of Mocha Dick.

In May 1839 the Knickerbocker Magazine, a popular publication in New York City, published a lengthy article about Mocha Dick by Jeremiah N. Reynolds an American journalist and explorer. The magazine’s account was a vivid tale purportedly told to Reynolds by the eccentric first mate of a whaling vessel.

The story by Reynolds was noteworthy, and it’s significant that an early review of Moby Dick, in the International Magazine of Literature, Art, and Science in December 1851, referred to Mocha Dick in its opening sentence:

The new nautical story by the always successful author of Typee has for its name-giving subject a monster first introduced to the world of print by Mr. J.N. Reynolds, ten or fifteen years ago, in a paper for the Knickbocker entitled Mocha Dick.

It’s little wonder that people remembered the tales of Mocha Dick as related by Reynolds. Following are some some excerpts from his 1839 article in the Knickerbocker Magazine:

This renowned monster, who had come off victorious in a hundred fights with his pursuers, was an old bull whale, of prodigious size and strength. From the effect of age, or more probably from a freak of nature, as exhibited in the case of the Ethiopian Albino, a singular consequence had resulted — he was white as wool!

Viewed from a distance, the practised eye of the sailor only could decide, that the moving mass, which constituted this enormous animal, was not a white cloud sailing along the horizon. On the spermaceti whale, barnacles are rarely discovered; but upon the head of this lusus naturae, they had clustered, until it became absolutely rugged with the shells. In short, regard him as you would, he was a most extraordinary fish ; or, in the vernacular of Nantucket, ‘a genuine old sog,’ of the first water.

The journalist describes the violent nature of Mocha Dick:

Opinions differ as to the time of his discovery. It is settled, however, that previous to the year 1810, he had been seen and attacked near the island of Mocha. Numerous boats are known to have been shattered by his immense flukes, or ground to pieces in the crush of his powerful jaws; and, on one occasion, it is said that he came off victorious from a conflict with the crews of three English whalers, striking fiercely at the last of the retreating boats at the moment it was rising from the water, in its hoist up to the ship’s davits.

Adding to the white whale’s ghastly appearance are a number of harpoons stuck in his back by whalers who failed to kill him:

It must not be supposed, howbeit, that through all this desperate warfare, our leviathan passed [unscathed]. A back serried with irons, and from fifty to a hundred yards of line trailing in his wake, sufficiently attested that though unconquered, he had not proved invulnerable.

Mocha Dick was a legend among whalers, and every captain wanted to kill him:

From the period of Dick’s first appearance, his celebrity continued to increase, until his name seemed naturally to mingle with the salutations which whalemen were in the habit of exchanging, in their encounters upon the broad Pacific; the customary interrogatories almost always closing with, “Any news from Mocha Dick?”

Indeed, nearly every whaling captain who rounded Cape Horn, if he possessed any professional ambition, or valued himself on his skill in subduing the monarch of the seas, would lay his vessel along the coast, in the hope of having an opportunity to try the muscle of this doughty champion, who was never known to shun his assailants.

Reynolds ended his magazine article with a lengthy description of a battle between man and whale in which Mocha Dick was finally killed and towed alongside a whaling ship to be cut up:

Mocha Dick was the longest whale I ever looked upon. He measured more than seventy feet from his noodle to the tips of his flukes; and yielded one hundred barrels of clear oil, with a proportionate quantity of ‘head-matter.’ It may emphatically be said, that the scars of his old wounds were near his new, for not less than twenty harpoons did we draw from his back; the rusted mementos of many a desperate encounter.

Despite the yarn Reynolds claimed to have heard from the first mate of a whaler, legends about Mocha Dick circulated long after his reported death in the 1830s. Sailors claimed that he wrecked whaleboats and killed whalers into the late 1850s, when he was finally killed by the crew of a Swedish whaling ship.

While the legends of Mocha Dick are often contradictory, it seems inescapable that there was a real white whale known to attack men.