Delia Easton is the main protagonist and the hidden main villainess of "Killer's Kiss", the 42nd book of R.L. Stine's original Fear Street series (published on February 1, 1997). She was an aspiring artist and the rival of classmate Karina Frye, her former best friend. Along with competing for a college scholarship, Delia and Karina were also both dating student Vincent Milano (each unaware of the other, though). Furthermore, Delia also became angered after learning that her younger sister Sarah was also romantically involved with Vincent, which was shown when she callously insulted her after catching the two together.
At first, it appeared that the unstable Karina was trying to destroy Delia's life, sabotaging her chances at the scholarship and tying her to her bed with rope in order to prevent her from attending Vincent's birthday party. Vincent himself was later found murdered at the site of said party, and it seemed that Karina had used Delia's lipstick to frame her. The aspiring singer was eventually institutionalized when Delia broke into her house and discovered tissues she'd used to apply her purple lipstick in a drawer, with Karina attacking her during one of her breakdowns before she was apprehended.
Later on, both Karina and her friend Gabe Denver decided to miss prom in order to visit Karina at the psychiatric hospital that she was institutionalized at. As the pair discussed how Delia had won the Conklin Award after Karina's detainment, the evil sociopath confessed all of her sinister deeds to Gabe, detailing how she had sabotaged her own auditions for the scholarship, used rope to put bruises on her wrists, and had also attacked Vincent after his party before killing her manipulative three-timing boyfriend by stabbing him in his chest with a knife. Delia then kissed Gabe's face multiple times and cuddled up to him, asking him if he was going to turn her in and subtly threatening to murder him next if he refused to keep her secrets. At that moment, however, a doctor standing nearby revealed that he had overheard her whole confession and was going to call the police. The deceptive villainess was presumably arrested and then imprisoned afterwards.
- "You didn't really think he would choose you over me, did you? Even in my clothes and makeup, you're nothing special." (Delia insulting Sarah after catching the latter and Vincent together)
- "I took charge. Don't you get it? I started with the small stuff. You know. Jamming the rat into my guitar and smearing purple lipstick over my paintings. Getting that rat was so gross! I had to dig through the big garbage bin behind the school. I could tell those little tricks wouldn't be enough. Karina was too pretty. And too talented. The judges loved her. So I had to do something else. Something more. Then I caught Vincent making out with my disgusting sister. Yuck. Just thinking about it turns my stomach. I guess that's when I figured out what I was going to do. I couldn't let Vincent get away with that. I couldn't let him kiss my sister in front of me. I was losing everything. Everything. Vincent. My sister. The award. I saw everything slip away... and then I suddenly knew what I had to do. I had to kill Vincent. I had to kill him for liking Karina better than me. And for kissing my sister. Kissing my sister... and if I could pin the blame on Karina—then all my problems would be solved!" (Delia revealing herself as a murderous and spiteful sociopath to Gabe)