A buttscab is the crispy little wafer of feces that clings to the anus of a cat. Sometimes these tasty little treats can be found on the ground in the shape of a brown cnowflake. Each one is unique but they're hard to find because cats are idiots and love eating their own shit.
LOL I just put a butt scab in your can of pringles.
That butt scab dangling off your siamese's butthole looks mighty delicious!