To me it's either a reference to a raccoon or a Maine Coon cat.
Once upon a time my ex and I were entertaining a long-lost friend who happened to be black (or AA, or person of color). During the evening I made a reference to not having seen him in a coon's age. The pregnant pause was.... um.... palpable. What!? It's a phrase that means a long time.
What's the origin of "coon's age"?
May 25, 2004
Dear Straight Dope:
Where does the expression "coon's age" originate? Is it a racial reference or does it actually pertain to raccoons?
It actually refers to raccoons. The expression "in a coon's age" dates to the early 1800s, and to the folk belief that raccoons are long-lived. My pal Colibri of the Straight Dope Science Advisory Board says, "References differ, but a wild individual raccoon might live up to 5 to 7 years (average survival being much lower, though, probably 2-3 years), and in captivity they can live up to 14-17 years. So their lifespan is comparable to that of a dog."
In the early 1800s, it's doubtful if anyone knew how long raccoons actually lived, and two to three years in the wild is not really very long. But raccoon fur is hardy and reasonably durable, which might have given rise to the belief of longevity.
Many slang terms use the term "coon" to mean raccoon. Their black eye-mask and nocturnal habits suggest anthropomorphic parallels, so we get the term "coon" meaning to steal or pilfer, for instance. The word also was used in the 1830s to mean a rustic, a country-bumpkin. In 1840, the coon was the figurehead of the Whig Party. (Where are the Whigs now when we need them?)
Unfortunately, many of those negative stereotypes were applied to black people, hence the derogatory term "coon," first used in the 1850s but more commonly heard after 1890. Some etymologists speculate that the term was used because of the raccoon's dark coloring rather than its real or imagined behavior. Whatever the case, the usage is highly offensive today - heck, it was highly offensive back then. For that reason, "in a coon's age" makes many people uncomfortable, notwithstanding its innocent origin. You might try "in a dog's age" or "in donkey's years" (British), which have the same meaning. Or "in a month of Sundays," which avoids animals altogether. Better yet, do us all a favor and come up with an original expression. We haven't had a novel way of saying "for a long time" in a coon's age.source
To me, the term 'coon' still references raccoons.