The criminal mastermind known as Proxima, a Grindalid female referred to as "Lady Proxima," oversaw operations from her hideout situated on Corellia. Her reign extended throughout the Imperial Era and the First Order-Resistance War. As the head of the White Worms, she enlisted young Corellians, whom she called "scrumrats," providing them with sustenance and a place to live in return for their involvement in her illicit schemes. Among these "children" were Han and Qi'ra.
Corellia was the world where Lady Proxima conducted her affairs. During her youth in the High Republic Era, she was a member of the Garavult Clan. She, along with other older Grindalids, aided in fending off the Nihil invaders from Corellia around 230 BBY. By 24 BBY, she had established the White Worms.
In 13 BBY, after failing to secure coaxium, Han was presented to Lady Proxima. His failure ignited Proxima's fury, leading her to instruct Rebolt to strike Han with his staff. Han defended himself, seizing the staff and declaring he would retaliate if threatened. Moloch then brandished his blaster, aiming it at Han. Qi'ra intervened, stepping in front of Moloch's weapon and advising against shooting Han. Subsequently, Han grabbed a rock, initially feigning it was a thermal detonator to intimidate those present. Proxima, however, saw through his ruse, calling his bluff and prompting him to hurl the rock through a window, allowing sunlight to flood the chamber and strike Proxima's face. This action resulted in burns on the left side of her face that lasted for years, forcing her to retreat into the water. Han then fled with Qi'ra, escaping the White Worms and fleeing outside the den on his M-68 landspeeder. Moloch, Rebolt, and other members of the White Worms pursued Han and Qi'ra. While they managed to capture Qi'ra, they failed to apprehend Han.
Doctor Chelli Aphra journeyed to Corellia and persuaded her former partner, Sana Starros, to set up a meeting between herself and Proxima, presenting it as a mere introduction. However, Proxima recognized Aphra from past encounters and was angered by her arrival. Aphra offered Proxima a peace offering, seeking information about a Path engine.
During the Galactic Civil War, Han, accompanied by Chewbacca, made his way back to Corellia in search of components for the Millennium Falcon. While conversing with Em-Five, Moloch identified Solo. Moloch took Han and Chewbacca captive and brought them before Proxima. Proxima informed Han that he would face retribution for his failure to deliver the coaxium he had promised her in 10 BBY, as well as for scarring her face by exposing her to sunlight during his escape. As Han spoke with Proxima, Chewbacca provided him with a thermal detonator, which he then used to detonate the window above her, once again exposing her to sunlight. The sunlight caused permanent burns to the right side of Proxima's face and left her blind in her right eye. Han and Chewbacca subsequently escaped, departing Corellia after being fired upon by Moloch.
Some time after the Cold War, Bazine Netal arrived on Corellia to inquire with Proxima if she knew the whereabouts of the Millennium Falcon. To coerce Proxima into divulging information about the Falcon, Netal captured one of Proxima's most skilled young White Worms. Consequently, Proxima recounted the time when Han returned to Corellia seeking parts for the Falcon.
Following the story, Netal expressed her displeasure with Proxima for failing to capture the Falcon. Proxima advised Netal to seek out a man named Ducain on the planet Jakku, as Ducain possessed knowledge of the Falcon's location. Netal then departed Proxima to locate Ducain.
Linda Hunt lends her voice to Lady Proxima in the 2018 Star Wars Anthology film Solo: A Star Wars Story. Jon Kasdan, the screenwriter, suggested Linda Hunt for the role of Lady Proxima, admiring her haunting opening narration of Shelley Duvall's 1989 horror anthology TV show Nightmare Classics. Kasdan had also collaborated with Hunt previously in his 1985 Western film Silverado. Initially, during the production of Solo, the character was named Mother Proxima, but the name was later changed to Lady Proxima.
Proxima's design underwent changes during the development of Solo. Jake Lunt Davies, a creature concept designer, revealed in an interview with StarWars.com that the initial concept for the Den of the White Worms influenced Proxima's appearance, including the possibility of her having underwater tentacles that could connect with her attendants. The creature effects concept team debated whether Proxima should resemble a worm or a serpent, and whether she should have scales or arms, but they consistently designed her to be dominant over Han. Ivan Manzella ultimately created Proxima's final design, while Davies designed her costume, drawing a comparison between Proxima and Fagin, a character from Charles Dickens' novel Oliver Twist, who also recruited children, providing them with food and shelter in exchange for their participation in criminal activities like pickpocketing.
Proxima shares similarities with Garris Shrike from the 1997 Star Wars Legends novel The Paradise Snare, penned by A. C. Crispin. Like Proxima, Shrike was a crime boss who offered Han Solo and other orphans on Corellia sustenance and shelter in return for their involvement in criminal activities on his behalf. Solo eventually rebelled against him and fled from him and the world as a young adult, mirroring his experience with Proxima. Crispin stated that Lucasfilm authorities informed her during the writing of the novel that Solo had been raised by a roving gang of thieves who forced him into crime, leading her to envision Shrike as the leader of that gang. Based on the information she received, Crispin believed that George Lucas must have had the parallels to Oliver Twist in mind when he decided that Han Solo was raised by such individuals and led into a life of crime.