“In 1818, while living in Kentucky, Audubon was visited by a wild-eyed fellow naturalist named Constantine Samuel Rafinesque, who had come to see Audubon’s drawings. He was courteously given a bed for the night. The household was scarcely asleep when great crashes were heard in Rafinesque’s quarters, and Audubon rushed in to find his naked guest bouncing around the room, swinging Audubon’s favorite violin at a number of flying bats, which he believed to be a new species. Either to avenge his battered violin or simply to play a practical joke, Audubon later described to Rafinesque a dozen imaginary fish and even provided drawings. Rafinesque copied everything down in his notebook, later published the discoveries. Audubon never gave his joke away, and scholars puzzled over the phony fish for years before deciding they were a hoax.”
- LIFE, Jan 29, 1951
I’m personally skeptical of both the “revenge” and “practical joke” hypotheses, leaning more toward the whole, Audubon was a known compulsive fabricator, thing.