About the Law and Buggy ideas.
When either Buggy or Law separate body parts, the mind always stays in the head. However, in this case, the mind is in the guy's legs, as they can sense people around him. I'm guessing this is a new devil fruit, sort of a parasite type fruit that allows the controller to latch on to animals and control them. Perhaps the other half is in some sort of rest state like Perona.