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He activates the device just as Julia is about to debate her opponent on nationwide television. However, Julia becomes a popular write-in candidate who wins by a landslide, forcing the Brain to change his plans and plant a microchip in Julia which he uses to control her into getting him in power. Upon which, he puts her into a chamber to evolve her to be like him and Pinky to be his wife and assist him in winning an election, giving herself the name Julia upon reaching agreement. Initially, Julia was an ordinary mouse until passing a test that the the Brain set up for her. She seems to be less interested in Brain than Pinky, the former of whom she despises, though she does show him some respect after letting him come up with a better one-liner, and was obviously uncomfortable going along with her ex-husband's plan after she read his script about having children build bombs, indicating that she does have some honor and decency. When Brain sarcastically comments on her plan to steal his code and activate the electromagnetic pulse, Julia mentions, when questioned, that she was accepted into the Iowa Writers' Workshop but decided not to attend because she "wanted real-life experience," implying she has a talent and/or skills in creative writing. Julia appears to enjoy wordplay and reading because she creates awful puns when threatening Brain, forcing her to backtrack for a better one, and says how she "sometimes gets into fights on Goodreads" in the same episode.
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But as a result of the Brain's deeds, Julia has evolved into a wicked mad scientist mouse who is out to get revenge on the two, combining the intellect of the Brain with the irrationality of Pinky. She had a heart of gold at first, despite being a genetically modified mouse, and she exhibited concern for everyone save the Brain. Her character embodied the greatest traits of all previous First Ladies. She also objected to the way he handled Pinky. Julia was presented as Brain's moral antithesis since she opposed his more cruel techniques, such as child labor and maybe world dominance. She has a straight tail like Pinky, but like Brain, it curves into a zigzag at the end. She is equipped with an electronic chip in one ear and an ear tag in the other, the latter of which is actually an obedience device worn by Brain to manage her. She spends part of "Reichenbrain Falls" dressed as Pinky and is briefly shown wearing a spacesuit otherwise, her costume is a spy catsuit and bare feet. She, like other female mice in the show, has a voluptuous figure and appears more humanoid than the two. She goes barefoot throughout the show, whether she is dressed or not. Julia is nude at the beginning and conclusion of "Mousechurian Candidate," but wears a green pantsuit on the campaign trail. Julia has brown fur on her back and a yellowish underbelly, as well as a brown spot around her left eye.
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