The Cat King is the main antagonist of the Studio Ghibli film "The Cat Returns". He is the king of the cat kingdom. Of course, he's not intentionally evil; he's just trying to repay the non-titular protagonist Haru after she had saved a cat from getting hit by a truck, for that cat turned out to be the King's son Prince Lune. His plan is to have Haru marry Prince Lune after this. At one point, he "fixes" the problem Haru has with marrying him by making her half cat, and making sure that the more she loses herself, the more cat-like she will become. After it is shown that Prince Lune had already chosen to marry a white cat named Yuki (another cat Haru helped, this time, when both were littler), the King asks Haru to marry him instead, she refuses. He keeps trying to keep her in the Cat Kingdom, but she eventually gets home with help from her friends.
In the English dub, the Cat King is voiced by Tim Curry.