In High School Horror Part 1, She first appears in the basketball court alongside Sheila and Lola. Later in the lockeroom, she calls Maddie a guy. The next day she, Lola, and Sheila beat up Maddie.
In High School Horror Part 2, She appears at Sheila's birthday party. While everyone else is only allowed to eat carrot cake, she and Lola are allowed to eat chocolate cake. A while after Sheila's murder, she and Lola decided to swim, only to find Sheila's corpse in the water. Thalia suggests calling the police and blaming Maddie for it. When the police officer is checking the security cameras, Thalia is about to "falsely" accuse Maddie of murdering Sheila, only find out that Maddie actually did it.
In High School Horror Part 3, She and Lola meet Vicky and team up with her.
In High School Horror Part 4, She, Lola, and Vicky are in the school on Sunday, planning on what to do to the kids. Lola anounces that Maddie is still alive, much to the glee of Vicky. Thalia suggests shooting Maddie with a gun but Vicky rejects the idea, saying that she wants to see Maddie suffer and decides to kill Maddie's younger brother, Alex. The trio sneaks into Alex's school and puts pills in the grape juice supply. Alex drinks the juice and passes out. The trio kidnaps Alex and cuts out his voice box. Alex wakes up, only to get decapitated by an axe. The three then eat Alex's corpse and go back to school where they sneak in the principal's office and make an announcement that Vicky rules that school and no one stops her or they will be killed.
In High School Horror Part 5, Vicky, Lola, and Thalia stand in the school. Vicky has gotten bored of ruling the school.Thalia asks Vicky what should they do, and Vicky's answers is that they should burn down the school. Thalia asks Vicky who is going to buy the gasoline and Vicky answers by saying, "Who said anything about buying?". The next day after stealing gasoline, the trio is confronted by XxdarkageknightxX who tells them to stop or he'll shoot Thalia, knowing that Thalia has been bullying Maddie before Sheila died and Vicky became the ruler of the school. Vicky is nonchalant about the threat prompting XxdarkageknightxX to shoot Thalia, killing her and making Vicky laugh at her death.
Thalia, Sheila, and Vicky's flesh were later used for Whet Faartz