I tucked the bottom and top in of a cardboard box big enough for my daughter to stand in. Tied 2 ribbons at the top for shoulder straps to hold it up. Dressed her in black pants, white socks (mid calf like a cat's socks would be) and white tennis shoes. She had a leopard coat and white gloves already and wore that.
I took a dowel rod and attached (the wonders of duct tape!) a rectangle piece of cardboard to the top of it and then taped the bottom of the rod to the inside back of the box For the sign (facing the front to see when she walked) I wrote "FREE TO GOOD HOME!".
We found a cat face of felt at the dollar store, but one can be easily be made/or just whiskers drawn on the face. When she walked, she held the front of the box/white gloves curling over the edge looking like a kitten in a box peering out.
It was a HUGE hit! She looked adorable! We had most of the items ourselves so the total cost was $5 (cat face, ribbon shoulder straps, dowel rod) Can't beat that!
Thanks to MotherGusa for this inexpensive and fun idea.