Julianna Keaton was a recurring character on Beauty and the Beast. She was portrayed by Gloria Votsis.
Julianna was a scientist, working on a formula for rapid cell regeneration to cure even the most deadly diseases. While she was developing the serum, Liam Cullen tricked her into injecting him. Though he tried to kill her, Julianna escaped and was determined to find a way to stop Liam.
Julianna started experimenting on random people throughout New York, hoping to find somebody who could help her take down Liam. She had varying degrees of success, able to turn some into superhumans, but also hurting or killing other people. After some of her experiments were subdued, Julianna believed Liam was after her, and sent her experiments to find out who he sent. Two of her experiments, Bob & Carol Hall, later found a potential subject that they promised to deliver to her in exchange for an antidote. Before they could, both were killed.
Julianna wanted to find out who was after her, and purposely created a virus of the serum that would cause an outbreak, hoping to draw out whoever killed Bob & Carol. She found out about Vincent Keller and Catherine Chandler coming after her.
When Heather Chandler, Catherine's sister, was looking for a job, Julianna used this to get close to Heather by posing as a potential employer. She threatened to kill Heather unless she told Julianna who Catherine and Vincent were working for. Heather admitted that Vincent was a beast, under coercion.
Catherine & Vincent were captured by Julianna's henchman, and Julianna quickly tranquilized Vincent before he could attack her. Julianna tried to get Catherine to admit they were working for Liam by threatening to kill Vincent in front of her. Catherine insisted she didn't know who Julianna was talking about, but Julianna didn't believe her and tried to kill Vincent. Before she could, though, Vincent's friend, J.T. Forbes, stopped her and Vincent was able to kill Julianna's henchman, while an infuriated Catherine beat Julianna unconscious.
Julianna later woke up in the hospital under arrest when Vincent and Tess Vargas, Catherine's friend, showed up. Julianna realized they weren't working for Liam, and said that Vincent was the one that had to stop Liam, but only if he was injected with the superhuman serum she created. Vincent and Tess didn't believe her, though, and left. Julianna later escaped, and went to the 125th precinct, where she used her confiscated lab equipment to create another serum. Vincent & Tess showed up to stop her, but Julianna escaped before they could.
Julianna later showed up outside the precinct when Catherine was on her way to the church to marry Vincent. She kicked Catherine back and jumped into the limousine, with a syringe at hand containing the serum formula she synthesized from inside the precinct, and threatened to kill Catherine unless she injected Vincent so he could help her stop Liam, hoping to use the bride-to-be as leverage to get Vincent to comply. Catherine, though, fought back and subdued Julianna. This time around, however, Julianna offered a greater challenge than the last time she fought against the NYPD detective, repeatedly kicking Catherine in the face, while the limo's limited internal space placed both combatants at a distinct disadvantage over each other. Catherine holds long enough for Vincent to arrive and restrained Julianna. She & Vincent brought Julianna to the church, where J.T. tied her up by one of the radiators to stop her from escaping.
J.T., Tess, Heather, and Vincent all agreed to turn Julianna in after Catherine & Vincent's wedding. Julianna, though, was desperate to get away so she could stop Liam. She insisted Liam would show up, and find her soon, but they all refused to listen. However, during the wedding ceremony, Liam found Julianna, and brutally killed her.