At least two prototypes of the vessel were built. The ship itself was a modified Romulan warbird, with its propulsion systems and command circuitry largely identical to the typical Romulan warship of that era.
The bridge consoles were still present when Trip Tucker and Malcolm Reed were able to gain access to the bridge. It was quite small in comparison to Enterprise NX-01. The vessel was designed to be remotely controlled from Romulus by an Aenar pilot via telepathy as chief among its many modifications. The drone ship was controlled from an operations tower in the Romulan capital by the Aenar pilot, who was forced to pilot the warship against his will. Two Romulan officers oversaw its operation, as it was of special interest to the Romulan Senate.
The drone ship's bridge was dominated by a large subspace transceiver to receive its remote orders from Romulus. The interior was confining and cramped, with bulkheads exposing data cables at various points throughout the ship. Because of its lack of crew, much of the ship was devoid of a life support system. In addition, the drone ship featured an auto-repair system that allowed it to correct damage sustained during combat.
The vessel was a formidable adversary in combat. Its weapons were very powerful for its time, inflicting major damage on its targets. Its ability to self-repair proved an asset during battle, where damage could begin to be corrected almost immediately. Without the need for inertial dampeners to protect a crew, the drone was much more maneuverable than the average manned vessel, capable of dodging photonic torpedoes with deft barrel rolls.
In 2154, the Romulan drone ship was given the task of destabilizing potential political alliances between Earth, the Andorians, and the Tellarites. It was equipped with an advanced multispectral emitter system which, when activated, allowed the ship to assume the appearance of nearly any other vessel. The drone ship's disruptors used tri-phasic emitters, which could mimic the weapon signature of a wide range of other ships, from Andorian particle cannons and Tellarite disruptors to Starfleet phase cannons.
Using these unique abilities, the drone ship threatened to provoke a war between the Andorians and Tellarites, first by destroying Andorian commander Shran's warship Kumari in the guise of a Tellarite vessel, then by attacking the vessel carrying the Tellarite ambassador, this time posing as an Andorian warship. The Romulans later threatened to draw the Humans, and potentially their allies the Vulcans, into the conflict, when the drone destroyed a Rigellian scoutship while mimicking the appearance of the starship Enterprise.
Ultimately, the drone ship's presence may have caused what the Romulans had hoped to avoid: an alliance against them. The appearance of a common enemy united the Andorians, Tellarites, Humans, and Vulcans, who attacked the drone and eventually forced it to withdraw to Romulan space.
The Romulans subsequently launched a second drone ship, which was used in combination with the first to attack Enterprise. Both drone ships were destroyed when Jhamel, an Aenar, used Enterprise's telepresence unit to interfere, asking the pilot – her brother, Gareb – to stop his attack. Realizing his sister was on board the ship he was attacking, Gareb was strong enough to overcome the Romulans' control, and had the two drone ships attack each other, destroying one and enabling the Enterprise to destroy the other, thwarting the Romulans' attempt to destabilize the region.
Writer/Producer Mike Sussman conceived the Romulan drone ship as a modified Romulan Bird-of-Prey which could somehow camouflage itself but didn't have the ability to disguise itself as other craft. (Star Trek: The Official Starships Collection issue 39, pp. 13 & 17) However, the producers wanted something slightly different than a customized Bird-of-Prey. (Star Trek: The Official Starships Collection issue 39, p. 13)
The drone ships' ability to emulate other vessels was devised by Mike Sussman. He later recalled, "While I was working on the episode I was trying to come up something else about the ship – was it just super powerful?" Believing Romulan vessels shouldn't have cloaking devices as early as the 2150s, Sussman wanted the drone ships to use a different form of camouflage. He therefore contemplated other technologies that the species might have developed. "I started thinking about holotechnology and shapeshifting," Sussman continued. "That seemed related to cloaking technology so I thought it was fair game and we hadn't quite seen that on Star Trek before. I pitched that to the producers but they were very lukewarm on it and told me to come up with something else. Without that element, it was very straightforward – it's a bad guy spaceship and it's causing trouble. The whole thing that the holographic element gave me was that there was a war brewing between the Andorians and the Tellarites [....] How would you do that if it wasn't one ship? Did the Romulans steal a ship? Were there different ships? It just solved so many problems if you could buy into this technology." Despite the producers being hesitant about the drone ships' holographic shape-changing ability, Sussman wrote it into a story outline for "Babel One" and, once the producers read it, they finally approved the technology. "I remember Manny [Coto] said, 'You know what? It works.' It gave the story more layers," commented Sussman. "If you think of it as a murder mystery, the ship was able to frame other races for its crimes. It kind of made sense because the Romulans were very duplicitous." (Star Trek: The Official Starships Collection issue 39, p. 17)
In the final draft script of "Babel One", the Romulan drone ship was described as "a sleek, compact but powerful-looking alien vessel [....] Although the design is unfamiliar, we'll eventually learn this is a prototype Romulan ship." Also, the ship's subspace transceivers were scripted to be "numerous spiky projections jutting out of the marauder's hull, like so many raised quills on a porcupine." The same script declared, too, that the craft's bridge was to be "a redress of the Romulan Command Center" from where the vessel was controlled. In the original script of "United", the prototype drone ship was called the Raptor by Admiral Valdore on at least one occasion, though this reference was omitted from the final draft of the script. In that teleplay, the drone ship, while evading weapons fire from Enterprise, was likened to "a ninja evading bullets."
The Romulan drone ship was a reuse of the chaotic space hulk from VOY: "The Fight". This was at the behest of the ENT producers, who selected the design from an Eden FX catalogue of all the obscure models available to them for potential reuse. The producers thought the reuse of the chaotic space hulk could be justified because its previous appearance had only been a fleeting glimpse of it and had been more than six years prior, though the primary motive for recycling the design was to save money. Robert Bonchune, from Eden FX, agreed with the reuse, not only owing to the quickness of its previous appearance but also because it looked extremely different from the ships depicted before, which was important because the visual uniqueness of the ship matched how it had been described in the "Babel One" script. (Star Trek: The Official Starships Collection issue 39, pp. 13 & 14)
The ENT art department created a drawing of the vessel's exterior in a primarily green Romulan color scheme and with the ship's surface covered in holographic emitters. After this was approved, the image was passed on to Robert Bonchune. According to him, the craft was then given a memorable nickname. "I got a sketch of that ship as a Romulan ship," Bonchune reflected. "John Eaves [I think] wrote 'FLEA' on it and that's what it became known as. But officially it was the Romulan drone and that is it." (Star Trek: The Official Starships Collection issue 39, pp. 13-14)
After receiving the illustration, Rob Bonchune began modifying the relevant computer-generated model at Eden FX. "I could have had our modelers Pierre [Drolet] or Koji [Kuramura] do it," noted Bonchune, "but that would have just added to what was on their plates." Since Bonchune himself was already working on the ship's modifications, he opted to continue doing so. (Star Trek: The Official Starships Collection issue 39, p. 14)
Because importance was still placed on budget-saving, Rob Bonchune didn't spend too much time altering the ship's CG model. "I was changing colors, adding antennas, and rebooting the lights, without rebuilding it [....] All those things were in place. It was really just changing colors," he explained. "I illuminated some antennas I didn't like and changed the internal lighting." The biggest differences in the CG model took place because, in the six years since it had originally been built, processing power had greatly increased. This allowed Bonchune to make the holographic generators on the hull as elaborate as he wanted. Thus, the model took advantage of the relatively new ability to turn on ray-tracing lights, which had been impossible to do for episodes of Star Trek: Voyager due to insufficient render power. "So I upgraded the lighting," stated Bonchune. "I put some interactive light in for the holoprojectors and we could have them glowing, and I made some changes to the point lights at the end of the bigger antennas. It didn't take long. We gave them exactly what they wanted – a ship that cost virtually nothing." (Star Trek: The Official Starships Collection issue 39, p. 14)
The intention to make the drone ship seem at first as if it isn't Romulan influenced the animation of the vehicle. "We made it move in a very different way," Rob Bonchune observed. "It could do these weird flips and turns." Bonchune felt these erratic movements were identical to how a UFO maneuvers. (Star Trek: The Official Starships Collection issue 39, p. 14)
As evidenced by the first draft script of the ultimately undeveloped film Star Trek: The Beginning, "hundreds" of Romulan drone ships were to have appeared in that movie. Their design was described as "a hideous vessel (it looks like a colossal flea)". The drone ships were to have followed close behind the Romulan flagship (which would have been a Romulan Bird-of-Prey) in an assault against Earth, initially hiding behind Earth's moon, Luna.
In the 25th century timeline of Star Trek Online, Drone Ships are used by both the Romulan Star Empire and the breakaway Romulan Republic. In the Republic, drone ships are deployable by the Scimitar line of Dreadnought Warbirds. Like the original versions, drone ships are able to use their multispectral and tri-phasic emitters to mimic the appearance and weapon properties of various opposing ships, including Miranda-class frigates, Borg probes, Klingon Birds-of-Prey, and others. Unlike the originals, though, the drone ships are controlled remotely by the crew of the ship and do not need an Aenar pilot to function.