An Echo Papa 607 drone
The Echo Papa 607 was an advanced weapons system developed by the arms dealers of Minos. Intended to be a complete weapon of war, the Echo Papa 607 was able to automatically send out small drones to gather intelligence, capture enemies, and mount attacks. The main advantage of the system was its progressive adaptability; each time a drone was destroyed, data on enemy equipment and tactics was returned to the parent system and a new drone was manufactured which improved on the previous model, countering the enemies abilities. The process of replacing a drone took twelve minutes and through this "evolution", the drones eventually became impossible to stop.
The drones were able to monitor enemy communications and project interactive holographic illusions of individuals familiar to its enemy in order to gather intelligence. To capture a target for further study, a drone could encase a target in a force field that kept it in stasis. The drones were armed with directed energy weapons and protected by deflector shields. They were able to attack both ground troops and starships. Some of them were also equipped with cloaking devices. A single cloaked drone was able to cause heavy damage to the USS Enterprise-D.
A still active Echo Papa 607 system was present underground on Minos in 2364, long after the Minosian civilization had been wiped out. It destroyed the USS Drake and nearly destroyed the USS Enterprise-D before Captain Jean-Luc Picard realized the attack was a demonstration for a potential buyer. The system shut down after he agreed to "buy" the device from the planet's automated sales merchant. (TNG: "The Arsenal of Freedom")