Fur-bearing trout

The fur-bearing trout (furry trout, shaggy trout, polar trout, beaver trout) is a cryptid species of trout reported to exist in polar and sub-arctic waters, as well as select lakes of certain northerly states of the United States of America, noted for the distinctive fur coat, white or brown, that it is said to grow. It has been popularised as an object of taxidermy art.

John Bunker's Polar Trout (1913)
"One of the freaks of the north country is a fur-bearing fish of the trout species, according to John Bunker of Northwood Center, N. H., known as the Isaac Walton of that state, who recently reached Boston from two months' exploring trip in Greenland. He brought photographs and actual specimens of the strange fish, which he has called polar trout. This particular denizen of the polar regions resembles a square-tailed trout in shape and gameness, and reaches ten to fifteen pounds in weight. The skin is covered with a fish brownish fur, resembling the texture of moleskin. This fur is slightly spotted with white, as is a young seal in the spring. Bunker says this fact first led him to call the curiosity a polar trout. Bunker caught all three specimens, two in a river and one in a small headwater pond, about two hundred miles north of Baffin's Bay."

This story circulated as an aside in many newspapers throughout the United States from late 1913 and into 1914.

Fur-Bearing Trout of Iceberg Lake, Montana (1929)

 * https://babel.hathitrust.org/cgi/pt?id=coo.31924082002951&view=1up&seq=480&q1=%22fur%20bearing%20trout%22