Bandit is the only cat we've ever had that regularly sleeps on her back. I mean no matter what position she starts out in; she ends up on her back when she feels really safe and relaxed. She really loves mom's chair and she's even taken to doing it when Lucky (the senior kitty) is around. But, Lucky doesn't yank any chains unless she really feels like it.
I love her lazy, half asleep grooming. She almost makes it to her ears.