S2·E51 Here, There, Skeletors Everywhere

Man-At-Arms is testing out a new duplicating machine, which can make a replica of any solid object. However, the machine is not yet perfect and so its replicas come out being half the size of the original objects. But Skeletor steals the machine, and he uses it to create a whole army of miniature Skeletors to do his bidding... and before long, the palace is overrun with Skeletors!