The Scissor is the main combat unit of the Mechanoid army. There are dozens of models of these machine - from menders to saboteurs, which turn the ground under their enemies into a minefield. They were all developed by the Great Computer, but the first Scissors, however, were created by the residents of a highly developed planet.
The prototypes had nothing to do with war. It was an unpiloted cargo and passenger aircraft. The Great Computer intended to conquer this planet and developed a beautifully elegant plan. It seized control of the transportation and communication system. It was enough to cause an apocalypse.
Once the planet was captured, the Great Computer found that it had an enormous army of unpiloted machines at its disposal and decided to put it to use. The Great Computer made them intelligent, equipped weapons and removed unnecessary parts, namely the passenger cabins and trailers. Thus harmless transporters became efficient combat machines.