Petlinks Scratcher's Choice Hanging Tower Cat Scratcher Toy with Catnip
I think my cats missed the memo on what a scratcher is? They ignored it while it was hanging and now mostly literally scratch their backs on it now that it's on the floor, but I got it for entertainment, so it definitely provides that for them. They're pretty good at missing the point.
the cats like this, and the price is right, but it falls off the door knob frequently