My friends have nicknamed her "The Bowling Ball with legs." She kills rodents (occasionally) but doesn't eat them - which I know is hard to believe.
It's true - because she is so lazy, she literally will watch a mouse cross the floor, and she watches it, and nothing moves except her neck. I've told her spectating is NOT part of the lease agreement. (I live way out in the woods.) She'll camp out next to a mole hole on the lawn for hours, waiting until some really dumb rodent exits right into her paws. She also kills but doesn't eat them, either, just leaves them where I can step on the corpse in bare feet in the middle of the night.
And no, I don't overfeed her. She was an abuse/neglect case as a young cat that I took in about 8 years ago. When she hit adulthood and kept gaining poundage, I took her to the vet, and they reviewed what food I was feeding her, how much, and ran about $1100 in tests - and they are totally stumped as to why she's a blimp. No hormonal, glandular/organ issues apparent - she's just passed through puberty (got spayed) and kept growing widthwise. It's sad she's going to have the "big one," or have her liver or kidneys eventually go, as she's a gentle sweetheart. But even being able to go outside at will, she is no couch potato - she's the couch.