Drones are the servants of The Intrusion who have been deliberately mutated by Intrusion infestation in order to make them more insectoid -- larger eyes with multiple pupils, arms with pincers, an external skeleton, and so on. As the body of a Drone becomes more insectoid, so does their mind, as the mutation causes Drones to slowly lose their identities and become assimilated into the hivemind of The Intrusion. When this process is finished the Drone will no longer retain any individuality and will become yet another vessel for The Intrusion's consciousness.
In The Great Game Verse, Rick from A Tangled Web became a Drone sometime before The Thirteenth Apostle. Matthias Judas had to kill a hive of Drones in The Thirteenth Apostle as well. A Drone called The Grasshopper confronted Dewitt, Axiom, and Kallaway in their respective Game Master Tournament blogs.