"Jackrabbits were named for their ears, which initially caused some people to refer to them as “jackass rabbits.” The writer Mark Twain brought this name to fame by using it in his book of western adventure, Roughing It. The name was later shortened to jackrabbit."

https://www.nationalgeographic.com/animals/mammals/facts/black-tailed-jackrabbit#:~:text=Jackrabbits%20were%20named%20for%20their,was%20later%20shortened%20to%20jackrabbit.