How do I make a charakter with immovable parts?

Hello, I’m doing a player that’s consist of ball (body) and head on top of the ball. I have already rolling ball (from tutorial) and I would like to add a head that stay on top while the ball-body is rolling. May I ask for some tips or hints?

I’have dealed with it already, if someone would be intrested :
I attached 8 small balls to the head and they soround the body so the head does not fall.Then I disabled Mesh Renderer of balls. There is a screen :59134-image2.jpg