Years ago, I had a big, dim, black cat. He was a very sweet boy, and his lack of intelligence was part of his charm. Once, while playing 'chase me', he ran behind the not-floor length-curtains, and sat, smugly hiding, while we all roared with laughter at his fat bum hanging out the bottom.
Despite his lack of smarts AND being very rotund, he was the most amazing hunter. My anti-cat neighbour changed his mind when fat boy dispatched several rats. He also whizzed past me in a black blur in the garden once, and I had to unclench his jaws to set a terrified bird free. He also once brought a pigeon indoors, which shed many feathers in fear, and I had to shoo it out of a skylight, because it had been struck motionless on the top of a cupboard in fear.
He was a lovely old boy though. I miss him.