The Mutant Massacre or the Morlock Massacre was a major Marvel Comics crossover, which took place during the summer of 1987. It involved the superheroes The X-Men, The New Mutants, X-Factor, Power Pack, Thor, and Daredevil and was featured for two or three issues that summer in all those heroes' comic books.

The Massacre began when a team of mutant supervillains, known as the Marauders decided to attack mutants just for the sport of the kill. It was revealed a few years later that the Marauders had been working for the then-unknown mutant villain Mister Sinister, who had commissioned them to take out other mutants in an attempt to lure Scott Summers and Jean Grey.

The Marauders began their assault on the Morlocks, a group of weak, elderly, and horribly grotesque and disfigured mutants, who lived in the sewers of Manhattan. They followed the Morlock named Tommy back to the Morlocks' main tunnel location, before killing her.

During the Massacre, Sabretooth, who was a member of the Marauders, had a skirmish with a gang of local children beneath the Hell's Kitchen section of the city. Daredevil managed to save the children and did enough damage to Sabretooth to send him out of the tunnels.

Meanwhile, X-Factor, who was also living in Manhattan at the time and whose building's basement connected directly to the Morlock tunnels, ventured into the tunnels to help save as many Morlocks as possible. Callisto, the Morlocks' leader, and several other Morlocks, including Sunder , Artie Maddicks , and Leech, were brought safely back to X-Factor's headquarters and remained with them, while The X-Men and Thor battled the Marauders in the Morlock tunnels. Leech and Artie remained as students with X-Factor permanently.

X-Men Shadowcat, Nightcrawler, and Colossus were badly injured in the tunnels, and Angel from X-Factor had his wings impaled by the Marauder Harpoon .

Against the orders of their then-leader, Magneto, some members of the New Mutants also ventured into the Morlock tunnels during the Massacre to help however they could. They met up with the X-Men and X-Factor there, who also encouraged the younger members of the New Mutants to leave the tunnels.

The Massacre was also the first time that the X-Men realized that Jean Grey was still alive.

Legacy

Comic book fans have cited the "Mutant Massacre" storyline as a definining example of the "grim-and-gritty" style of superhero comic book storytelling that dominated the industry during the late 1980s and early 1990s.

Critics of these stories have called it depressing, gloomy, even nihilistic. They believced that the Morlocks were annihilated for no real reason other than to provide audiences with bloody, violent entertainment.

Others argue that the crossover had many ramifications for the involved titles, including Angel's transformation into the dark Archangel in an attempt to restore his wings, and an overhaul of the current X-Men lineup (Kitty Pryde, Colossus and Nightcrawler were all badly injured, and in the later months they were replaced by Psylocke, Dazzler, Longshot and Havok). They also point out that most of the Morlocks killed were nameless characters and no real characters (such as Callisto) were killed.