It's a paw shaker.

[rebeccacceber]

...

 

[jcat]

That's a good one! We have a secured balcony, and I've seen the old "paw shake" many a time. It's never stopped the cats from going out there in the winter, though Mogli keeps his trips short. His predecessor loved the snow, but would meow for me to pick him up when his feet got too cold.