Luna

Luna is a robotic puppet built by the Technomites who serves as the main antagonist right up until it's defeat in the spin-off game Ratchet & Clank: Size Matters. It is initially introduced as a young, innocent girl doing a report on heroes on Pokitaru in an attempt to lure Ratchet into saving it.

Luna is voiced by Nicole Sullivan in English, and by Satomi Kōrogi in Japanese.

Ratchet & Clank: Size Matters
A young girl approches Ratchet and Clank during their vacation at Jowai Resort and explains that she is doing a report on heros. Unable to resist her cute charm, Ratchet agrees to serve as her hero and does some heroic work by taking out robots and whatnot. She also encounters Captain Qwark, who explains to Ratchet and Clank that he never knew his parents. Suddenly, a bunch of robots appear and chase after the girl. Ratchet goes after them to save her, but is too late as she is kidnapped and taken to Kalidon. During this, she drops a technomite artifate, causing Clank to beleave that the robots wanted her because of her item.

In Kalidon, the girl is held in a cell guarded by Mungo. Ratchet and Clank defeat the beast and free her, where she finally introduces herself as Luna. When Clank suggests on getting out of here, Luna explains, in an adult woman's voice, that she didn't get a chance to tell her "friends" about their heroic deeds. This confuses Ratchet, but Clank thinks of it as her speech being improved and continute to help her speak properly. However, Luna grabs a gun and stuns him with it. She then tells Ratchet that they now have "everything they need", then summons her friends over to take Ratchet to the Medical Outpost Omega and Clank to Metalis.

Just before the MOO is destroyed, Ratchet views Luna's last journal entry. In it, Luna explains to her leader, Otto Destruct, that the tests are completed and she is now returning to Challax. She also reveals that she created one test subject and it took 27 warriors to destroy it.

In Challax, following the defeat of the Dropship, it is revealed that the evil little girl that Ratchet and Clank are going after is actually a fake. Luna is actually a robotic puppet and ship being used by the technomites for their own crimes. Just before the duo can speak with the technomites inside the head, Luna suddenly blasts off.

They chase it to the Dayni Moon, where the technomites inside of Luna explain why they did this: they were getting bitter that they remain uncredited with their technology. Since Ratchet kept on destroying them all, they decided to create their own army of Ratchets. The technomites then attempt to murder Ratchet using Luna, but it is defeated after a difficult battle. Clank soon attempts to hack into the Luna puppet, but malfunctions as a result of a powerful security program, allowing the technomites inside the puppet to invade him.

Luna is not heard from again, implying that it was later scrapped as a punishment for Otto's crimes.

Personality
Luna is portrayed as cold and heartless, and will do whatever it takes to accomplish it's goals, even if it meant disposing anybody who gets in it's way, such as with Clank after he tried to help "her" with "her" speach. Despite it's coldness, Luna is very loyal to it's master, Otto Destruct.

Before it is revealed to be a villain, Luna took on the personality of an ordinary girl, and could not pronounce certain words. "Her" cheerfulness and cute appearance would help lead Ratchet into "her" trap.

Trivia

 * By collecting seven Skill Points, you can access the cheat "She's on Fire!", which will result in Luna being in flames. This does not happen in cutscenes, however.