There is a feral cat here that looks like his/her hips are swinging back and forth when walking. He/she also looks like her back side is up higher than her shoulders. I can't get close to him/her. It hisses and growls at me. He/she seems to get along with the other cats including some kittens. Is there something wrong with it? None of the other cats have a swing like this when walking. This cat is less than two years old.