As with many of the Best Internet Things™, we can’t bring ourselves to care if this Craigslist post is tongue-in-cheek or wholly sincere. Either way, it suggests a brilliant mind at work.
Really, I defy you to concoct a better description of a ferret than this:
Found (assuming) pet. Some sort of cat snake? Long and nimble but with dryish fur and cat teeth. Seems to like cat food, but isn't a cat. Please come take this off my hands it smells weird.
As of press time, the “cat snake” had not been claimed, and is likely slithering about somewhere.