Lyn is not human, she is Irken. She was traveling through the galaxies, where she was forced to go to Hobo 13 by the Tallest, when her ship abruptly ran out of fuel. (She learned later that RiRi, her SIR, emptied it out to make room for her collection of smashed guitars.) Lyn crash-landed in Danville and freaked out, because she hadn't thought out a disguise. After a day of observing normal human behavior, she created her disguise but couldn't set up base anywhere. Mrs. Williams, her current foster mother, found her wandering the streets and invited her into her home. After a large brouhaha, Lyn finally gets materials from the Tallest and sets up base, leaving a note on her bed at the Williams household: "Bye humans."
Lyn is power-hungry and
likes has to be the leader. She has heard of Operation Impending Doom II and is unofficially part of it, rather like Zim, who is not really an invader. She is also kind of pushy.
Lyn's disguise looks rather similar to Tak's. She has mastered the art of disguising herself well, not like Zim, who simply wears contacts and a wig. She has purply-black hair, which becomes longer and curlier as she stays on Earth, and steel-blue eyes, and wears a dark purple and black shirt-dress and black pants, failing to disguise her PAK. She also has extremely long eyelashes.
It is also not mentioned how she disguises herself, although it is said she wears contacts like Zim.
Lyn has bright blue eyes and the typical green Irken skin.
PAK: Lyn is equipped with a PAK just like every other Irken, but she has made a few modifications and it can produce a force field that can deflect most anything that comes near it.
Lenses: Lyn's human-disguise contact lenses have optional X-ray vision.
Mind Control/Memory Blanking: Like Tak, she has the power to blank a person's memory and/or force them to do something. The device is disguised as an earring when she is in her human form.
She and Zim are somewhat friends, and Zim is the only one (besides Dib, who can smell an alien from a mile away) who knows Lyn's secret identity. Although after she betrays him and foils his plan to crash the moon into Earth, they become bitter rivals. She also hates Zim more when she learns how he once nearly succeeded in killing Dib. They are now currently in a bit of a love triangle with Dib.
Lyn is as close as you can get to best friends with Dib. She has not outright told Dib that she is an alien, but Dib has put two and two together and guesses that she is Irken. Lyn also has a crush on Dib, but it is not known if he returns her feelings. However, he does show a bit of emotion when he doesn't try to expose her like he does with Zim.
RiRi is Lyn's custom-made SIR unit (remember, she isn't officially part of Operation Impending Doom 2). Lyn, however, is horrible at building robots, and so RiRi has a personality rather like GIR's, though Lyn can sometimes (keyword is "sometimes") get RiRi into duty mode, even if it's only for a few minutes. RiRi disguises herself as a bunny and talks to GIR a lot.
KiKi (formerly RiRi II)Edit
KiKi is Lyn's actual functioning SIR unit that is perma-locked into duty mode. She is given to Lyn by the Tallest when they think she is capable of dominating Earth. KiKi eventually overdoes the whole "protecting-Lyn" thing and self-destructs; specifically, she implodes. Lyn claims she is a newer model, and that they "make less mess" that way.
Lyn thinks her adoptive sister is a dork and does not spend much time around her. She is relieved to get away from Claire and her mother once she has materials to build a base.
Mrs. Williams is too frumpy in Lyn's eyes and though Mrs. Williams makes a huge effort to get Lyn to talk, Lyn ignores her.