License To Taxi?

Hello All,
Perhaps someone hereabouts can settle a discussion I had with a fellow
passenger on an airliner the other day: Suppose there's a 747 parked
at a gate and they need to taxi it over to a maintenance area. Does it
require a licensed pilot to taxi a plane that large (or any plane, for
that matter) on the ground? We are stipulating that the plane is not
going to take off -- merely drive from one part of the airport to
another. Also, if pilots do NOT usually perform this task, then who
usually does?
Thanks for any info to settle this!