The same person that said he never sleeps with the same woman twice.
dons a perfect prosthetic duplicate body of his and frames him for two murders. It goes further in that she claimed to still love him, but believed that by being inside an exact copy of his body she had his "ghost" inside of her. Then she tries to kill the real Pazu. It's not quite made obviously apparent that the real Pazu won the fight.
Ray Palmer and his ex-wife, Jean Loring, in Identity Crisis. She gets committed to Arkham Asylum at the end. (Despite, er, not even living in the same state. Apparently there are no other asylums in the DCU.)
Tanis and Kitiara have this kind of relationship in Dragonlance, and feelings definitely linger on both sides (though in Kitiara's case, those feelings aren't much deeper than "lust and amusement"). From a technical stance, Kit's less "psycho" than "amoral and ambitious", but she still fits the trope.
Given how Kitiara becomes insanely jealous after hearing that Tanis is traveling with his ex-girlfriend Laurana (especially after hearing how incredibly beautiful Laurana is) and how this jealousy causes Kit to become obsessed with Laurana to the point of relentlessly stalking the elfmaid and trying to give her a Fate Worse Than Death, Kitiara definitely fits as a "psycho."
Fox Mulder had two of these — all right, so the first one was mostly just annoying, but the second one turned out to be working for the Government Conspiracy and having some kind of weirdly ambiguous relationship with the Smoking Man.
It's becoming increasingly easy to read The Master from Doctor Who as the Doctor's ex from hell. They were at school together, used to be best friends, and the Master is utterly obsessed with being the centre of the Doctor's attention. His two appearances in the revived series have both involved him doing horrific things to the Doctor's favourite species - in the End of Time, he went so far as to turn every human on Earth (except Wilf and Donna) into a copy of himself.
The likely explanation for the behavior of the so-called "Virgin Queen" in The Shakespeare Code.
For a few episodes Blair Waldorf on Gossip Girl becomes this to Chuck. Most people thought it was fair enough, since he was giving his new girlfriend incredibly expensive watches, crediting her with making him a better man and treating her like a queen, when he'd whored Blair out to his uncle and then slept with her greatest enemy.
Another Whoniverse example: John Hart, Jack's ex-"partner" who shows up in the second season premiere of Torchwood. He reappears in the finale, holding Grey, Jack's long-lost brother, hostage and tearing Cardiff apart for no apparent reason but to get Jack's attention. It turns out to be a subversion, as Grey is the one in charge and has a bomb fused to John's wrist, forcing him to obey when he'd rather be anywhere else.
Jack's bad luck with men continues in Torchwood: Miracle Day, when his boyfriend Angelo's Catholic gayngst leads him to do terrible, terrible things.
How I Met Your Mother parodies this in "The Platinum Rule": at the end, Barney assumes Wendy the Waitress is this. She is actually taking their break-up really well, but he interprets her total maturity about the matter as a facade hiding a desire to murder him—for at least two years.
Being as the show focuses heavily on dating, a number of straight examples show up, as do a number of women who never quite become girlfriends.
A fun variation comes up when Lily starts following the girl Marshall's interested in, making Lily, by all rights, the crazy ex. At the end, Marshall concludes that Lily is one of the craziest people he's known. It's the episode they get back together.
iCarly: Lewbert's ex-girlfriend Marta Trundel in iFind Lewbert's Lost Love.
Oz. Unit Manager Tim McManus forms a brief liaison with prison guard Claire Howell. When he tries to break off the relationship she assaults him in his office (to the delight of watching inmates), then charges him with sexual harassment when he tries to fire her. Howell's later actions definitely cast her in the role of a villain — she assaults (and in one case murders) inmates, as well as using them for her own sexual gratification whether they want it or not.
24. Two characters, Jack and Tony, dating the same person, Nina.
Davina from Material Girl Tv Series its revealed at the end of the series that most of her attepts to hurt Ali were in fact directed at Marco, Ali just got in the way.
Virginia from Sunset Beach. She even tried to have her ex's current girlfriend impregnated by another guy using a turkey-baster! in a memorable scene.
Havoc and Sakura in Renegade.
The Vampire Diaries has Katherine Pierce, who was a former love interest of both Stefan and Damon Salvatore during their human lives. Katherine enjoys torturing and playing with both Stefan and Damon and has threatened Elena numerous times. Katherine appears to be obsessed with Stefan in particular and seems to be both jealous of Elena and in competition with Elena for Stefan's affections.
Rose from Two and a Half Men both fits and subverts this. Although becoming friends with Charlie, she does manage to drive away his love interests and refuses to give up. Plus, every main character has called her crazy at some point. She's also pretty civil in her stalking, despite it being creepy.
After Dexter finally cut it off with Lila in Dexter, she nearly killed him and his girlfriend's children.
Niles's ex-wife Maris from Frasier probably qualifies, although more subtly: when she begs for him to come back to her, and he rejects her on the grounds that she has treated him like dirt all his life, she goes into a Tranquil Fury and proceeds to utterly screw Niles out of every cent he has with a team of Amoral Attorneys, just for the sake of revenge (she was filthy rich already).
Also Niles' second ex-wife Mel, who after feeling justifiably humiliated when Niles abandoned her to run off with Daphne Moon, exacted her pound of flesh by insisting he go through the motions of marriage with her until such time as she felt they should seperate and divorce. well, everyone said she was an expy of Maris...
In Zoey 101, we have Chase's short-lived girlfriend, Rebecca. Admittedly, she was psycho while she and Chase were still dating; she demanded Zoey no longer have any contact with Chase, and that Chase stop being friends with Zoey. It was the reason they broke up. Rebecca, of course, took this to mean Zoey was the reason they broke up, and in a later episode ends up blackmailing her into doing all sorts of embarrassing things.
In one episode of Boy Meets World, Shawn becomes the target of three of these who band together to sabotage his latest relationship because they think he is leading her on like he led them on.
Gabe of The Office is a psycho ex boyfriend. He becomes one after Erin breaks up with him. He follows Andy, (whom Erin really likes) to the men's room and threatens him and follows Erin into the ladies room and pleads for her to take him back.
Vera Bates of Downton Abbey to the extreme. She refuses to let Mr. Bates divorce her, blackmails him for everything he owns and then pulls an I Lied and tries to ruin his reputation and those of his girlfriend Anna and the family that employs them anyway, and finally commits suicide in order to frame him for her murder. All this to a man who went to prison in her place for theft beforehand.
"Before He Cheats" by Carrie Underwood, particularly with the double standard - imagine the same situation, genders reversed; how much vandalism do you see the cuckolded guy getting away with? While the singer's violent response in celebrated in the music and implied to be without other consequence.
Also arguably, the Dixie Chicks' "Goodbye Earl." Though Earl was hardly any sort of hero (especially with what he did to Wanda), I wouldn't want to be those girls' next boyfriend.
And also to Carl Johnson, although he never actually wanted to be her boyfriend.
Shel Jelavan is this to Zayne Carrick in Knights of the Old Republic. However, she's sort of sympathetic, and they do genuinely patch things up once the collossal misunderstanding is resolved.
Adele from Arc Rise Fantasia has a definite air of this about her. She was only ever a girlfriend in her own mind (and hopes), but evidently that was enough to trigger a violent murderous storm of Yandere.
Klaus Wulfenbach and Lucrezia Mongfish/the Other in Girl Genius. Ironically, she was villainous enough before and while they were involved, and changed sides about the time they broke it off. Then returned to the new level of villainy and turns out to be still attracted to him.
Shannon in Echo Chamber's Trope Of The Week series has an entire episode dedicated to her psycho ex nature. She stalks him, threatens other girls he's seen with (Dana in particular), and seems to believe they are still dating. But the kicker? She forced him to propose to her. Oh, and she regularly cheats on him. Hooray for the Double Standard.
One could take the above spoiler as Tom proposes to her, but then gets cold feet and runs off. He takes Shannon back and now they have sex every so often.
Hell, Terra period. She was much worse in the comics! When she had the Titans (aside from Nightwing) captured, Gar pleaded with her, only to have her not only laugh in his face but sneer that kissing him "made her want to puke." Even better is that she was actively boinking Deathstroke (who was actually afraid of her). Poor Gar still can't fully acknowledge she was a traitor all along.
Comics Terra doesn't really apply to this trope since she was psycho before Changeling met her and any romance between the two of them was all an act on her part. Animated Terra however fits the trope to a T. She was pretty much on the neutral side of things, agreeing to sell the Titans out (well four of the five) as a favor to Slade for helping her control her powers, but not exactly on the evil side until Beast Boy told her she had no friends which turned her over the dark side completely until her Heel Face Turn three episodes later.
Goliath and Demona of Gargoyles, with emphasis on the "psycho"
This is a case where feelings do still linger on both sides, but both characters recognize that they're now too different to ever be an item again (trying to kill each other almost every time you meet will do that to you). Doesn't stop the shippers.
Simultaneously subverted and inverted in this story going around about Azura Lakin, a woman who slashed her ex-boyfriend's throat with a broken beer bottle, killing him, but isn't going to be charged with homicide because she did it as a response to his choking her, attempting to re-enter the apartment that she and her sister pushed him out of after he choked her, and moving towards her as if to choke her again.
Arguably, anyone can be the Psycho Ex regardless of their mental health. It's just a matter of perspective.