“Glee” co-creators Ryan Murphy and Brad Falchuk are ramping up the casting on their FX pilot, “American Horror Story”, booking Shelby Young in a recurring role as a “mean girl,” writes THR.

Young, whose credits include The Social Network and “Days of Our Lives”, will play Leah, a pretty senior and leader of the mean girls who torment Violet Harmon (Taissa Farmiga).

“The mysterious thriller revolves around husband and wife Ben (The Practice’s Dylan McDermott) and Vivien Harmon (Friday Night Lights’ Connie Britton) who move their family from Boston to a haunted San Francisco home in an attempt to rebuild their family after a miscarriage and affair.”

Frances Conroy and Alexandra Breckenridge recently joined the cast — both playing Moira O’Hara, a housekeeper who has worked at the haunted home at the center of the drama for years. Moira will appear as a woman in her 60s (Conroy) to Vivien, while a younger version (Breckenridge) will appear to Ben.

Young joins a cast that includes Evan Peters as mysterious teen Tate Langdon; Jessica Lange as the Harmons’ nosy neighbor; and Denis O’Hare as Larry the Burn Guy, a former resident of the home.