Myra Santelli is the secondary antagonist of the 2012 Disney Channel Original Movie, Girl vs. Monster.
She was portrayed by Katherine McNamara. Myra Santelli is the selfish and popular girl who clashes with Skylar Lewis. Besides being beautiful and dressed in the latest fashion, Myra is the lead singer of Ryan Dean's band, The Backbeats. When she is checking the banners and posters for the Halloween concert The Backbeats will perform at, she expresses frustration at the standard of being crooked and having its smaller than the band name. Myra insists on fixing the flag and lace it to Ryan to give upward momentum, despite his protests calling for help Skylar. She ends up falling down the stairs and it hurts the neck, leaving her in a neck brace and is unable to perform at the concert. Later, Myra is possessed by Deimata, she used Myra as a container for throwing his evil plan for world domination. When Deimata frees itself from the body of Myra, Myra apologizes to Skylar and begin to forge a friendship towards the end.
After this, Myra, Skylar's rival, who is at home with a broken neck is eating ice cream. Soon, the red smoke comes out and it transforms into Deimata. She then controlled Myra and goes to the party where she publicly insults Skylar of being nervous to sing at Ryan's party and Sadie comforts Skylar after she runs out, embarrassed. A possessed Myra sings in Skylar's place and turns to Theodosia and Bob (Sadie and Henry's monsters). Myra falls downstairs after Deimata leaves Myra's body as Skylar and Sadie find her. Myra informs them about Deimata and how she can possess people- like she did with her. Skylar thanks her, and she and Sadie rush to save the people upstairs. Skylar and her friends try to fight off Deimata, but she doesn't seem able to be stopped. Although Skylar has overcome her fear, she soon realizes Deimata is still feeding off of her parents' fears—about Skylar's safety. Once Skylar gets her parents to trust her, Deimata is weakened and the three friends defeat her and capture her. At the end of the movie, Henry and Sadie are shown having no fear by doing what they are scared about doing the most. Later that day, Skylar and Ryan sing at Ryan's party in his basement. Myra became a friend to Skylar.