I wonder if the torso of the KittyCatS is flexible so this tail chasing can be actually done.
I believe a real cat is bend in the direction it is chasing it's tail.
Tail chasing would be one of my number one favorite add ons also indeed kitties that interact with eachother and a sit on lap pose like a cute curled up kitty.
But I don't think the torso can handle that last one either.