Kit Morrissey is the main villainess of "Cat", book #45 of R.L. Stine's original Fear Street series (published on May 1, 1997). According to Kit, she was one of the last known shapeshifters on Earth, mostly taking the form of a cat. She was also shown to be a part of a family of felines, all living together in a house in Shadyside. While in her cat form, Kit hung around the gym of Shadyside High to watch basketball player Marty, who she had grown obsessed with.
But one day, after Kit accidentally tripped Marty as she ran across the court and caused him to sprain his knee to where he would have to sit out an upcoming game, Marty and his two friends (Dwayne and Barry) chased after Kit, with the chase culminating in Marty accidentally dropping Kit to her death. But Kit, having a cat's trademark "nine lives", came back to life, now vengeful against Marty and his friends.
As Kit (now in her human form) began a relationship with Marty, she also targeted Dwayne and Barry for their roles in her death, clawing both boys to death in her vicious cat form. Kit also used her powers to make other cats follow Marty on several occasions and followed Marty to his community service job at the animal shelter (having been forced to do so as punishment for the gym incident), making the animals there become vicious in his presence and even making the cages open at one point. Kit made her villainous reveal while Marty was at the shelter, first making the animals go wild again before stepping out and announcing that it was now Marty's turn to die. After revealing her powers and her fixation on Marty, the evil Kit transformed into her cat form and began attacking Marty, scratching up his face. But Marty was able to save himself by releasing Brutus, a vicious dog that had recently been brought to the shelter, and allowing him to kill Kit. Marty had his injuries treated in the hospital and he went on to play in the basketball tournament the next night, but during the game, the evil Kit reappeared at the game in her cat form, implying that she had once again returned from the dead to come after Marty.
- "That's true love, Marty. And how did you pay me back? You dropped me off the bleachers. You tried to kill me. You didn't know that I'm blessed with nine lives." (Kit revealing her obsession with Marty and her desire to get revenge after he killed her)