We got adopted by a new mom with three kittens, and one of them was much rounder and chubbier than the rest.

18 years later, and they're all gone except that little chubby one, who still looks young, even though she's 18, blind, and arthritic. The last time we took her to the vet, they were like "Are you sure she's 18? She looks a lot younger." We're sure, we knew her when she was still nursing.

Those roly poly ones tend to be the healthiest.