He likes the shape.
Jasper likes that the turnip has a tapered end that he keeps trying to chew on and can get a better grip on. He also likes when I try to take it away from him. He jumps around a lot and gets good exercise when I try to do that. We are just playing inside for now until the weather improves. We also alternate playing with a blue and orange rubber ball with a hole in it. When we are done playing I put the toys up on the counter. If left out he ignores them until I play with him. By not leaving them out all the time he seems to really enjoy the play time we have.