Lor is a young Earth girl with an addiction to sci-fi literature. She is the mortal enemy of Anj and Dib's rival.
Lor was mysteriously separated from her parents at a very young age when they went shopping and never returned, leaving her with no family or people to care for her. This is why she spent much of her time trying to make a name for herself. She became a vagrant orphan, educating herself through television and old books- many of which were science fiction. Through the gathering of the "facts" in the books, she concluded her parents had been abducted (although this is not certain). She swore revenge on all otherworldly creatures.
When she grew older, she joined the Swollen Eyeball network, going under the codename "Agent Twistheart." Unlike Dib, she kept her paranormal study somewhat secret, allowing her to be less antisocial. Lor also adopted a stray werewolf, which she turned into a cyborg, naming it Moldvort. She attended Skool, where she eventually spotted a strange, homely brunette girl who attempted to befriend her as part of her secret study on the Earth's species from Irk in Dib's Crazy Little Friend. Lor coolly allowed Anj to sit with her at lunch. While walking alone on her way to scrape together her meal, Lor passed Zim's base where Anj resided, spotting Anj and Krom out of disguise. However, she was unable to see Zim or GIR at the moment, which is why she does not focus as much on them.
The next day, Lor confronted Anj on her origins, to which Anj replied, "Prepostreous girl, I am a human like everyone else here." Zim added nervously, "Yes....everyone." Dib watcheds Lor quietly confront Anj and became interested in her. The two become the other's only real friend due to their shared interests in the paranormal. Dib shared what he knew about Zim and Lor shared what she knew about Anj. Using Dib as her "Large-headed little boy pawn," Lor was able to capture Zim, Anj, Krom, and their SIRs and plan to hand them in to the S.E.N. for rewards of fame, fortune, and recognition, so that she "would have dozens of potential families waiting to serve my every need!" Dib began to lose trust in her past this point, as she never used real resources on her paranormal research (only sci-fi books), refused to give Dib any credit after he helped her capture the Irkens, and had led him on in such a convicing way he may have developed a crush on Lor. Because of this, Dib vowed to work together with Zim, anj, and Krom to defeat Lor, eventually banishing her to a hole in the ground.
Lor appears somewhat frequently in the Invader ZIM: Agents of Doom series. She is, like Tak, a prominent antagonist to Dib, Zim, and Anj. She is competitive against Dib in many of her appearances, such as in Ka-Boom Of Doom where she competed against the three in the Skool science fair. Other appearances include her trying to expose Anj, much like how Dib pursues Zim, but less explicitly.
Lor is notorious for being the test subject for Anj's "live smeet birth" experiment that created Babz.. She carried a baby smeet in a flesh sack on her back after Anj secretly implanted the "smeetus" onto her.
Lor can be described as officially insane due to her lust for attention regardless of who she has to hurt to get it. She also has minor issues with being alone. Lor likes to manipulate people to do what she wants them to do. She loves science fiction and monster hunting, and has actually succeeded in capturing a few monsters, i.e. Moldvort, her cyborg werewolf.
Lor seems to target Anj more than Zim, but nonetheless dislikes Zim for getting in her way.
Lor used to be friends with Dib as seen in Dib's Crazy Little Friend, but now they have becomes full-out paranormal rivals. Lor is Dib's human enemy number one and vice versa. However, they may have a crush on each other.
Lor hates Anj as much as Dib hates Zim and vice versa. Lor constantly tries to infiltrate Anj's lab, discover her secrets, etc to expose her to the world for profit and fame. However, she constantly fails.
Lor doesn't care much for Krom, since he is barely grown from being a smeet. She attacks him mainly due to the fact he is usually with Anj.