Hand tools and fabrication machines
It is a good friend to have. You can feed him food you don't like and he can give you a massage. He (or she) is a VERY good friend. It also can move around.
how to build:
Take your 9v connector and solder it to the vibr. motor.
Then tape the motor to the edge of the handle.
And finally, attach your 9-volt battery securely to the brush and connect the connector. Place it on a firm surface and watch it scurry around.