Luna is an antagonist in Size Matters initially introduced as a support character. Posing as a small child doing a school project report, she was a technomite robot that was used by Otto Destruct to lure Ratchet into a trap and extract his DNA. Luna continued to support Otto Destruct's plan, until her defeat at the hands of Ratchet and Clank.
Luna met Ratchet and Clank while they were taking a vacation in the Jowai Resort on Pokitaru by taking a photograph of them. She presented herself as an innocent schoolgirl, with a clear lisp, who was doing a report on heroes, assigning the two the mission "Fight some robots", in which they would fight so she could get some pictures for her schoolproject. Ratchet reluctantly obliged. Later, when Ratchet and Clank ran into Captain Qwark, she overheard him mentioning that he never knew his real family. Shortly after this, a technomite dropship and several guard torsos captured her, staging an abduction, but reporting that they were taking her to Kalidon.
Ratchet and Clank managed to find the coordinates to the planet thanks to a technomite artifact she dropped, which led them to a Mechanoid Factory. There they fought a beast named Mungo, and rescued Luna from a cell. There, Luna suddenly changed her tone of voice to be much more sophisticated, confusing them. She promptly stunned Clank, who was later dumped on Metalis, while Ratchet was captured and taken to the Medical Outpost Omega for his DNA to be extracted. Sometime after, Luna herself traveled to the Medical Outpost Omega, where she reported to Otto Destruct on the clones' progress, after it took twenty-six of their best robots to take down a single Ratchet clone.
After Clank rescued Ratchet from the outpost, the two traced Luna's coordinates to a Technomite City on Challax. There, Luna was located within the city, stored within one of the largest towers. In "Explore the miniature city", Ratchet and Clank eventually discovered she was a robot, but before they could confront her, she activated rocket boosters and flew off to the Farming Cooperative on Dayni Moon.
In "Catch Luna", Luna tried to stop them by setting loose were-sheep to attack Ratchet and Clank, as well as activating dangerous machinery inside of a barn. They continued to pursue her, until she made use of a vehicle which doubled as both a plane and a combine harvester. In ""Disable" Luna", Ratchet and Clank ran through fields of wheat to avoid her, before she confronted them. There, she explained that the technomites were tired of being taken advantage of by the galaxy, and told them that they would be unable to stop Otto Destruct's clone factory.
After defeating Luna, Clank attempted to interface with her to find the coordinates to the Clone Factory. Upon doing so, he was electrocuted by Luna's access nine protocol, and infested by the technomite soldiers that had boarded her on Challax. Ratchet used the Shrink Ray to head inside Clank in order to defeat them and repair him.
Luna takes on the appearance of a schoolgirl with red hair and four pigtails, and a small antenna on her head. She is dressed in blue overalls and a baby-pink shirt, with white and yellow shoes, carries a teddy-bear on her back (similar to how Ratchet carries Clank on his), and uses a camera resembling a Polaroid. Her form is convincingly organic, though in the back of her head is a concealed door where technomites board to assume control.
Luna is a loyal henchwoman of Otto Destruct. She is very deceptive when fooling Ratchet and Clank as to her real plan, and shows no remorse in her actions, taking delight in having fooled them into a trap. All of her actions prior to kidnapping them on Kalidon are theatrics; she pretends to be a helpless victim while the technomite robots leave clues as to her whereabouts. When explaining her plan to the duo, she expresses that the motivations were out of the technomites' vengeance at being ignored by the rest of the galaxy, a feeling of resentment she apparently shares. However, she seems unaware of Otto Destruct's true intentions of becoming the most intelligent being in the galaxy.
When introducing herself, Luna speaks with a childlike voice and a lisp, struggling to pronounce the "s" sound in some words, giving the impression of youth. When not putting on this act, she has two different voices: a more sophisticated woman's voice, which she uses both in the presence of Ratchet and Clank and when talking to Otto Destruct, and a robotic voice, which she seemingly only uses to communicate as a technomite robot.
It is unclear if Luna has autonomy, or is merely a shell controlled by other technomites. Though it is shown that Luna is boarded by other technomites through a door in her head on Challax, she also sent a message to Otto Destruct as herself when reporting on the progress of the Ratchet clones in the Medical Outpost Omega. Unlike the rest of her theatrics, there is no evidence that this recording was planted or was meant to be seen by Ratchet and Clank, and it reveals plans Destruct had regarding Captain Qwark that he would not have intended them to be aware of. This suggests that Luna is actually an autonomous subordinate of Destruct who reports on her progress regularly.
Luna's main function and capability is in recording footage of Ratchet. Although floating cameras follow him as seen on Ryllus, she also takes pictures of him on Pokitaru with her camera, and the recorded footage is played back in the Medical Outpost Omega. This could suggest the camera she uses, which takes the appearance of a dated camera that can only take photographs, is actually more advanced. It is also possible, as she was present for the conversation, that she reported back to Otto Destruct that Qwark did not know his real family, allowing Destruct to deceive Qwark. Luna is also equipped with thrusters on her feet that are capable of flight, to the extent of interstellar travel as she was seen to fly from Challax to the Dayni Moon. She otherwise used them to safely cross gaps in her schoolgirl disguise, as seen on Pokitaru.
Luna makes use of a vehicle that is a combination of a fighter plane and can transform into a combine harvester, as seen on the Dayni Moon. This vehicle switches interchangeably between the two forms, but has a deceptive appearance; much like her camera, it takes on the form of a dated plane resembling early real-world aeroplanes.
Behind the scenes
Luna appears in volume 2 of the Ratchet & Clank manga.