Gia mahan
Gia Mahan was a recurring character from "Full House". She acted as the main antagonist in her first two appearances and became an anti-hero during the final season. It was mentioned that Gia was held back for a few years in Junior High.

Gia and her two friends came in the restroom to ditch class and smoke cigarettes. When she offered Stephanie Tanner one, she refused. She considered her a 6th Grade baby and gave her new friend an ultimeum; it was either Stephanie or Gia. She chose Gia. The next day, Gia offered her a cigarette, but decided to cut down. While Stephanie trash-talked back to Gia, she and her two friends left the restroom angry.

In the hallway, Gia was shown to have fallen for a new boy in school, but he wanted to date Stephanie instead. At the house, she came over and demanded that Stephanie must call off the date or else. After refusing to listen to her, Gia spread a rumor around school that the boy only wanted to date Stephanie, because she paid him $20. The next day, Stephanie chose to get revenge on her by spreading Gia's bad grades around school and titled it "Dishonor Roll". Afterwards, after seeing Gia in tears, Stephanie felt remorse and at the smash club, she became friends with her.

In the final season, it was revealed that when her parents divorced, Gia felt insecure and it led her into acting like a bully in the first place.