Justine Victoria Biagi is a 17-year-old punk rock girl who uses the in-ring name Scab. On the first day of auditions, she claims to be 19 years old. She is a fan of Sam's exploitation films and has a romantic relationship with pizza boy Billy Offal. The relationship hits a rocky patch when Billy criticizes Sam as a hack. ("This Is One of Those Moments") Later in the series, Justine reveals herself to be Sam's illegitimate daughter, as he had a one-night-stand with her mother Rosalie after being kicked out of a Black Panther Party rally in Sacramento nearly two decades ago. Her sole purpose of joining GLOW was to meet him.
After learning that he is sleeping with Rhonda Richardson, she steals the camera that Bash bought him and places it in Rhonda's locker, hoping to frame her. Both recognize the act for it is, though Rhonda thinks that she is jealous of their relationship and some sort of stalker with a crush. ("Live Studio Audience")
After this revelation, she no longer participates in GLOW as a wrestler, instead playing small parts in the show as a teenage girl named Lisa. She also goes back to school at the insistence of Sam. One day, Rosalie spots her on an episode of the show and storms in Sam's house to bring her back to Sacramento. After being allowed to attend the school dance, Justine is talked out of moving out to New York with Billy and decides to go home with her mother.
In Season 3, Justine pays Sam a visit and gives him her own screenplay. After Sam quits from GLOW, he helps Justine sell her screenplay to a film company and invites Ruth to audition for the film, but Justine ultimately decides to cast someone else for the role.
Around Christmas-time, Sam gives her a gift - adoption papers. Although he is biologically her father, it isn't legal because his name isn't on the birth certificate. He tells her that he talked this over with Rosalie and he wants her to have an inheritance. To his delight, she signs the papers.
Behind the scenes
Justine Biagi's actress, Britt Baron, stated that the only thing she knew about her character when first starting the program was that she was clearly lying about being 18. She felt that her character had transformed in the program's third season, but as February 5, 2020 doesn't know anything about the program's fourth season