Psycho Lesbian

Anime & Manga

 * Miharu from Baka and Test: Summon the Beasts is crazily in love with Minami. Her solution to anyone who happens to get between her and Minami is to try to Murder the Hypotenuse.
 * Lan Asuka from Devilman Lady is an Anti-Hero version, who discovers and largely manipulates the lead character Jun Fudou, seems to be attracted to her, or at least her superpowers. She still tries to help Jun in her own way, nonetheless. In the anime, however, she is much more psycho, given that she wants to become a god and rapes Jun near the end.
 * The Season 2 premiere episode of Hell Girl has a cute high school girl being harassed by a unknown person. By the end of the episode, it's revealed that the seemingly nice school nurse, is sadistic bully with a perverted obsession with the high school girl. She threatens to pour acid of her face if she doesn't give into her. The girl is able to sent the nurse to hell.