Mantrid drones are hybrid organic and mechanical devices comprised of a single robotic arm, and a large orb-shaped control and flotation unit allowing them to hover and even travel through deep space. These multi-purpose drones were initially constructed in the service of Mantrid to act as replacements to his arms, allowing him to construct inventions and collect resources within his prison on Mantrid's World.
In Lexx 2.12 "Norb", it is revealed that the Mantrid drones are "a variation of class 23 Cluster drones, version 2.03. They have limited individual computational power but can share data, which means the more of them you have, the more capable they become. [They] are largely composed of complex and precise electronic circuitry ... [and] are capable of being damaged by high powered pulses of electromagnetic flux"
Individually the drones are relatively weak and easily destroyed, however, their ability to assemble more of themselves through a process of self-replication makes them extremely dangerous, as a small group of drones can rapidly grow into a large swarm capable of disassembling entire planets and solar systems for raw materials with which to create even more of themselves.
Mantrid drones are first encountered in Lexx 2.1 "Mantrid" in which they are simply present as replacement arms for Mantrid. Notably in the episode Mantrid makes a point of destroying a drone by having it smash itself to pieces, while later in the episode the drones battle an offspring of the Giga Shadow. When Mantrid's ship is launched at the end of the episode, a trio of drones are seen following in its wake.
Drones are present in most episodes of season 2, usually seen at the end of each episode as a large swarm that destroys any planet or space station that the crew of the Lexx have visited, before dispersing in a pattern identical to that of the symbol of the Divine Order.
In Lexx 2.12 "Norb" the child pilot Norb, having been killed and re-animated by Mantrid drones embarks upon the Lexx as a ploy by Mantrid. Once the drones are released they proceed to multiply, harvesting parts of the Lexx for materials. They are eventually stopped when the Lexx is able to fires its engines with a reversed polarity, directing the energy inward and destroying the biological components of the drones.
After the crew of the Lexx decides to stop running and instead fight Mantrid, in Lexx 2.19 "Brizon" they are met by the Bio-Vizier Brizon, who attempts to defeat Mantrid by overriding his drones using a symbol of the Divine Order created for controlling the various technology in use by the Divine Order. However, Brizon's attempt to defeat Mantrid ultimately fails.
The drones are last seen in Lexx 2.20 "End of the Universe" after they have consumed all of the matter in the entire Light Universe, except for the Lexx. They are ultimately destroyed when Mantrid furiously sends them all against the Lexx, creating such a heavy concentration of mass that a Big Crunch occurs, temporarily creating a Fractal Core through which the Lexx escapes to the Dark Universe.