During their brief settlement of SR388, the Chozo created a series of automatons to make their daily lives easier, to keep them company, to do difficult or dangerous work, and to guard and defend important sites and buildings. When the Chozo were forced to leave SR388 most of these automatons were left behind. Some of them deteriorated beyond repair while other continued their original programming or simply kept functioning without a purpose at all, becoming a hazard for the life of SR388 or any unfortunate visitor who might stumble on these machines. The droid designated Terminal Portable Operator (TPO) filled the same position as courier and message drones do in Galactic Federation civilizations, carrying messages and other information and is part of the Chozo’s ancient data network. When the Chozo were forced to leave SR388, several hundreds of these drones were left behind, but as most of the data network was either shut down or damaged these drones no longer had any instructions left to follow and now aimlessly roam the corridors of their master’s settlements.
Although not really designed for tactical engagements, the Chozo had equipped their small message droids with an electrostatic field generators in case they would have to defend the Chozo people. The electrostatic generator gives the TPO the ability to attack opponents with limited electrical attacks without damaging its own internal system which could have happened if the TPO simply had an electrically charged covering instead of an independent attack field. This attack is quite damaging to organic tissue and can also severally damage other machinery. But as the TPO was never really designed to be a tactical droid, it can easily be dispatched by energy or kinetic weaponry.