Although three of the Stepford Cuckoos made a barely-there cameo appearance at the very end of the film X-Men: The Last Stand (and fans rightfully felt robbed), all five of them make their presence known in the X-Men comics. The Stepford Cuckoos - comprised of Celeste, Esme, Irma "Mindee," Pheobe, and Sophie Cuckoo (also known as 5-in-1 and then 3-in-1 following the deaths of Sophie and Esme) - are mutant quintuplet sisters whose reputations precede them in the comics.
The Stepford Cuckoos, memorable mutants in their own right, stirred up all kinds of trouble for Professor Xavier and the students at Professor Xavier's School. It goes without saying that they've been up to some evil stuff - 10 of which have been listed here. Without further delay, here are the 10 worst things The Stepford Cuckoos have ever done in the comics.
10 Shaming Esme
Although this incident involves four out of the five Stepford Cuckoos it's still worth mentioning. In New X-Men issue #123, Esme Cuckoo, the second-eldest quintuplet, has been struck by the love bug. She's kissing the new resident, who claims to hail from Osaka, Japan, and her sister's are not having it.
So, what do they do? One of the sisters implies that Esme is "practically a slut," shaming her for supposedly falling in love. X-Men fans know that this relationship doesn't end well and her lover turns out to be a mutant-sterilization advocate but her sisters calling her a "slut" (among other things) was just rude.
9 Inappropriate Mind Control
In New X-Men issue #118, when X-Men comic fans first meet the Stepford Cuckoos, they're already up to no good. Emma Frost, also known as the White Queen, has been teaching The Stepford Cuckoos how to implant "deceptive erotic images" into the minds of those they consider to be enemies.
While they may not have come up with the idea, they certainly know how to literally weaponize lewd thoughts.
8 Taking Kick & Using Professor Xavier's Machine
In New Xmen issue # 137, Kid Omega has formed a villainous band of drug inhaling mutants that are seeking revenge for the death of Jumbo Carnation, a fellow mutant. Kid Omega, otherwise known as Quentin Quire, ruins human and mutant opening day at Xavier School by taking Professor Xavier and the school hostage. All the while, he's high on the drug known as "kick:" a drug which destroys the X-gene in all mutants and causes untimely death.
Meanwhile, Sophie wants to make things right by amplifying her mind using Professor Xavier's mind machine without his permission and also taking kick . The result? Sophie dies. And then there were four.
7 Evil Mind-Control & Murder
In New X-Men issue #141, the mutant detectives who were brought in to solve the murder of Emma Frost reveal that Esme Cuckoo - who was caught trying to leave Xavier school alone by one of the detectives - inhaled the drug kick before overtaking her sisters through mind control.
She also telepathically forced Angel, a mutant at Xavier School, to pull the trigger and kill Emma Frost. New X-Men readers also learn that Sophie tried to resist the attack on Quentin Quire and that lead to her death during the Kid Omega vs. The Stepford Cuckoos incident in issue #137.
6 Speaking Ill Of The (Presumed) Dead
In New X-Men 2004 issue # 18, The Stepford Cuckoos - at this point 3-in-1 in the story - come to console one of their fellow pupils about the presumed demise of Quentin "Kid Omega" Quire. They tell Brian, who they perceive to be closest to him, that they don't believe he killed himself because he didn't have it in him.
According to them, he doesn't have that magnitude of feeling in him, to feel loneliness or the pain of it. This is cruel as Brian is trying to put together the loss of Quentin, they're essentially mocking his life and memory.
5 Turning On One Of Their Own
In X-Men Pheonix: Warsong issue #5, a powerful force called the Pheonix has entered the 3-in-1, Celeste, Pheobe, and Mindee Cuckoo. Now, the three sisters are exhibiting new powers - flying and the ability to shoot fire.
They were lured to a location where hundreds of Cuckoo sister clones were in tubes, and, long story short, the Pheonix dove into Celeste fully, but was driven out by Emma Frost, Mindee and Pheobe. All this was for nothing because Pheobe and Mindee turn on Celeste for holding them back from attacking, saying they are 1000-in-1 and they only do what they were made to do (rather than feel).
4 Their Great Divide
In X-Men Regeneris, the sisters are greatly divided. Still reeling from the events of Chaos War, the 3-in-1 find themselves torn about where they should go and where they belong.
Pheobe wants to leave the school and Irma (aka Mindee) wants to stay. This left Celeste with the deciding vote on who would be part of a duo and who would be alone.
3 Esme's Deception
In X-23, Celeste, Pheobe, and Irma are feeling the loss of their two dead sisters, Esme and Sophie. So, deciding to resurrect them (a decision that at first appears to be of their own making), they take over the mind of Dr. Helen Marks and create two clone bodies from the DNA of their dead sibling's corpses.
The clone bodies rejected this effort, and the bodies expired at an alarming rate. After that try again, this time with a fitter body named Gabby. It is revealed that Esme has been controlling her sisters and everyone in the lab for her own gain.
2 Attack & Abduction
In X-23, The Stepford Cuckoos kidnap Dr. Helen Marks, for the purpose of bringing back to life their deceased sisters, Esme and Sophie.
When only one re-born sister survives, they set their sights on Laura and Gabby, kidnapping Gabby to use her body to become 5-in-1 again, and attacking Laura (as the only one standing in their way).
1 Excluding Mindee
In X-23, a half-dead and half-alive mutant version of Esme has sent Mindee to look for their next victim (Laura, who has managed to survive the blast). In her absence, Esme quickly creates a division between Mindee and the two remaining sisters (Pheobe and Celeste) by saying she won't tolerate weakness and outright telling her sisters that there isn't always strength in numbers.
This is ironic, considering Mindee was one of the 3-in-1 who helped bring her back to the strange and deranged state Esme found herself in.