In Micmacs, each member of Bazil's crew has a speciality. This includes Petit Pierre who can build impressive stuff (like automatons) out of just about anything. Each member assists in Bazil's plots using their talents. But Pierre's contributions are, to my memory, conspicuously absent.
We do see him helping out in raising a drawbridge. But all that we see him do is press a button. Did he render any other notable service?