The Morlocks have always been one of the X-Men’s more sympathetic villains. Introduced as a society of mutants who chose to live underground to avoid being rejected and persecuted by humanity, the Morlocks have understandable reasons for being so frustrated with the humans who live above them.

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Yet sympathy can only go so far. Although the Morlocks have worked together with the X-Men on a number of occasions, both as reluctant and willing allies, the mutant sewer dwellers have also committed no small amount of cruel acts toward Xavier’s mutant team, as well as toward humans… and even each other.

10 Kidnapping Angel And Poisoning Kitty Pryde

The Morlocks first made their existence known to the X-Men when they kidnapped Warren Worthington III, alias the high-flying Angel. The X-Men tracked the Morlocks to their underground tunnels, where they found the captive Angel and the Morlocks’ leader, Callisto, who announced her intent to marry him. During their twisted wedding ceremony, however, Storm would challenge Callisto for leadership of the Morlocks in armed combat, winning by stabbing Callisto’s heart.

Meanwhile, Kitty Pryde (then using the codename "Sprite") nearly died from illness inflicted on her by the Morlock called Plague, but was helped by the Morlock Caliban. After Storm’s victory, Kitty would recover when returned to the X-Mansion.

9 Trying To Marry Kitty Pryde To Caliban

Caliban, however, had fallen deeply for Kitty, meaning the Morlocks’ bizarre habit of forced marriages would continue. When she first met Caliban, Kitty had promised to stay with him forever in exchange for his help. Intending to hold Kitty to her promise, the Morlocks kidnapped her. Though Kitty regretted her deal with Caliban, she agreed to abide by it, knowing the Morlocks had a healer who could save the wounded Colossus.

Fortunately, Colossus was healed with the combined efforts of Rogue and the Morlock named Healer, and Caliban called off the wedding when he realized it would make Kitty unhappy.

8 Ritual Disfigurement

The Morlocks were engrained with the belief that their mutations made them “ugly.” Therefore, to symbolize the rejection of the surface world, every new Morlock would have their faces molded by Masque into something he felt was uglier.

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While the Morlocks considered the ritual a part of their culture, it also perpetuated the false idea that their natural appearances were unappealing. Worse still, Masque would usually force the transformation upon others. When Masque became the Morlocks’ leader, he would take his body molding ability to greater extremes, transforming dozens of his brethren into monstrous doubles of the X-Men.

7 Kidnapping The Power Pack (And Making Their Parents Forget Them)

In Power Pack #12, three Morlocks known as the “Drain Dwellers” kidnapped the PowerPack to replace Annalee’s murdered children. The kids escaped with Shadowcat and Nightcrawler’s help, but an undeterred Annalee had fellow Morlock Beautiful Dreamer wipe all memories of the Power Pack from the minds of their parents and neighbors in Uncanny X-Men #195.

Suspecting Dreamer’s involvement, the kids returned to the sewers, but were all kidnapped except Katie Power. The X-Men came to Katie’s aid, and learned Dreamer had also brainwashed the other Power Pack members into thinking Annalee was their mother. A fight broke out, but was resolved when Callisto (now friend to the X-Men) learned what the Drain Dwellers had been up to.

6 Tormenting Callisto

While working as Moira MacTaggert’s bodyguard, Callisto was sent by Banshee and Moira to seal the X-Mansion’s underground complex. Yet on her way, she was captured by Masque, who had assumed leadership of the Morlocks. Masque demanded she tell him the access codes to the complex. Callisto refused, leading Masque to psychologically torture her by repeatedly molding her body into his vision of beauty.

While viewed as beautiful to many, it was a transformation Callisto didn’t want, and she grew more frustrated still when it seemingly became permanent. Thankfully, Masque was stopped by Marvel Girl, Banshee, Forge and an amnesiac Colossus, the last of whom helped Callisto realize her new appearance had not changed who she was within.

5 Trying To Steal Jean Grey’s Body

On a separate occasion, Jean was led to the Morlock tunnels by a young Morlock named Lighting Bug. who sought to replace her body with Jean’s. Using a psychic construct shaped like the Phoenix Force, Lightning Bug tried to force Jean to give into her demands, but Jean managed to defeat the other mutant (and surprise herself) with a Phoenix energy construct of her own.

When Jean found Lightning Bug’s skeleton and learned the mutant had just been a child when she had been murdered during the Morlock Massacre (a.k.a. the Mutant Massacre), Jean vowed to give Lighting Bug a proper burial, despite their earlier battle.

4 Teaming Up With The Brotherhood Of Evil Mutants

Masque and his Morlocks would enter an alliance with the Brotherhood, then lead by the Toad, to take down both the human race and their common enemy, X-Force. While the Brotherhood ambushed Warpath, Siryn and Shatterstar during an outdoor training exercise, Masque, Thornn, and Brotherhood member Phantazia would sneak into X-Force’s hangar to blow it up. The rest of X-Force intercepted them, but Thornn and Phantazia distracted the team while Masque snuck away to continue the plan.

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Eventually, X-Force managed to get the upper hand, and Shatterstar plunged his sword deep into the Morlock’s body. X-Force then took Masque’s body to the Morlock tunnels, with Cable proclaiming him dead.

3 Beating Their Healer And Former Leader

After accepting the new appearance Masque had given her, Callisto had decided to live a normal life, rather than stay involved in anything X-Men or Morlock-related. Unfortunately for her, the Morlocks felt that Callisto had abandoned them, especially since X-Force appeared to have killed her successor. The Morlocks raided Callisto’s new home, declaring her a traitor, beating both her and the Healer for trying to warn her.

The Healer would give his life to use the entirety of his powers to heal Callisto’s injuries, but inadvertently reverted her body to its earlier form. Callisto headed to the tunnels seeking revenge, but would not have it, as she and the Morlocks seemingly perished when Mikhail Rasputin flooded their home.

2 Making A Child Mind-Control Morlocks

When the Morlocks attacked Callisto, Professor X decided the X-Men must find a way to convince the Morlocks to abandon their violent ways. Taking to the tunnels, Xavier and the X-Men’s Gold Team found the Morlocks in other disarray, attacking one another and Manhattan. Sensing psychic interference at work, Xavier separated from the team to investigate.

Eventually, Charles found the source of the Morlocks’ mental turmoil: a young Morlock psychic called Brain Cell, whom Masque had manipulated into controlling their people. Xavier helped Brain Cell gain control of his erratic thoughts, as well as free the other Morlocks from the young mutant’s control.

1 Acts Of Terrorism

Instead of dying from the flood that raided their tunnels, the Morlocks were actually teleported by Mikhail to a dimension called the Hill, where he molded their children into the fierce warriors called “Gene Nation.” Marrow returned home with one Gene Nation group to commit severe acts of violence, including murdering 33 people in a New York City nightclub and strapping explosive devices to several kidnapped humans in the Morlock tunnels.

Some years later, Masque would lead the Morlocks who still had powers after M-Day in planting explosives in St. Patrick’s Cathedral.

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