They can move, shoot, pick things up, open doors, and pretty much everything else that a Clyde can't do (since the Clydes are basically just floating cameras). After TOM’s experience with the Intruder, he felt it was necessary to build some robots that could do more dangerous work and/or combat, because the ever so fragile Clydes just weren't cutting it. Equipped with hands, weapons, and thrusters, DOKs can fly into dangerous situations in swarms, making it extremely hard for the opposing force to come out victorious.
During the Lockdown incident, the Absolution was caught in a tractor beam, rendering the DOKs useless with TOM unable to control them. Due to their ability to be remotely piloted, they were used by Toonami viewers to disable the tractor beam, which allowed TOM, SARA, and the Absolution to escape the clutches of the trash compactor.
The DOKs were last seen during the Trapped in Hyperspace event, in which Swayzak took over the Absolution and sent it on a collision course with Earth. Since that time, that particular version of the ship was destroyed and a new one constructed; though whether TOM or the Dronomeks from Orcelot Rex's ship rebuilt the DOKs afterward is unknown.