The Marauders are a group of super-powered criminals working on behalf of the interests of the villain Mister Sinister. Sinister had long devoted his life to the study of genetics and mutations in particular. Knowing of the existence of an underground community called the Morlocks, Sinister decided that their existence was compromising and diluting the genetic gene pool. To remedy this, he met Gambit, a thief that owed Sinister a favor for restoring balance to his formative mutant powers, to form a group of mercenaries into a team of Marauders that would work for him.
In one of the Marauders' first known activities, based on Sinister's interest in the genetic lineage of the mutants Cyclops and Phoenix, several members of the team hunted Cyclops' wife Madeline Pryor and child Nathan, she used her latent psychic powers to defend herself, but failed from stopping the kidnapping.
The majority of Morlocks trailed Tommy while Gambit led Sabretooth, Prism and Blockbuster down another path. The mercenaries began a systematic massacre of the population. Unaware of the Marauders' true intent, Gambit tried to stop them, but was attacked by Sabretooth. He was only able to save a Morlock girl (the mutant now known as Marrow) before escaping. The Marauders were confronted by the Morlocks' allies, the hero team X-Men, along with other heroes such as Thor and Power Pack. Ultimately, the X-Men and the heroes stopped the massacre, but not before significant causalities were sustained by both sides.
Later, another Marauder, Malice, attempted possession of the X-Men ally, Dazzler, but was defeated by Dazzler's friends in the X-Men. The Marauders went on to attack the X-Men's associate Polaris. Sinister had decided, unbeknownst to Malice, that the mutant would make a genetic match with Malice and allow the two to become permanently bonded. It seemed that Polaris had managed to single-handedly and ruthlessly defeat the team, but in fact it was Malice who had taken possession of Polaris and declared herself leader of the Marauders. Malice, in Polaris' body, led the Marauders on several missions, including a failed attempt to capture Madelyne Pryor, who reappeared in California and would be rescued by the X-Men.
When a demon invasion occurred in New York City, Malice/Polaris led a Marauder attack on the hero teams X-Men and X-Factor. Several Marauders who were believed to have died in previous battles had reappeared. The heroes defeated the Marauders, many of whom were killed during the battle, but Malice and Sabretooth escaped (the latter would never regroup with the Marauders since then). Months later, when investigating Sinister's facilities, the X-Men discovered that Sinister had kept genetic information of the mercenaries in order to create clones of them. Some of the clones were released, but the X-Men defeated them and they died.
Years later, Sinister activated several Marauders and had them chase the mutant who was escaping her indentured servitude to Sinister. They were confronted by the hero X-Man, and in the course of the battle, most of the Marauders were killed. The remaining member, Riptide, was sent back with implanted memories that Threnody was killed as well. Nevertheless, more Marauders later returned, and Threnody agreed to return to Sinister.
Various Marauders have appeared later. For example, Sinister disguised several Marauders as agents of the villain Apocalypse in order to trick the hero Cable into forming an alliance with him. Another time, Gambit needed to invaded another of Sinister's bases, and Scalphunter revealed that all cloned Marauders were genetically programmed to never turn against Sinister on penalty of death. Gambit turned to Sabretooth, who was never cloned, and the two invaded Sinister's base, after facing several Marauders as guards. Presumably, as long as Mister Sinister remains active, he will always have at hand a cloned army of Marauders in some capacity. The Marauders also play a major role in X-Men: Messiah Complex storyline. In Messiah Complex: Chapter One, they arrive in Alaska and kill some Purifiers with the loss of Blockbuster and Prism, without finding the specical mutant child. In X-Men #205, the Marauders battles the X-Men at Sinister's Antarctic base. In Uncanny X-Men #494, the Marauders track Cable and the baby to Forge's Aerie in Dallas, where they defeat Bishop and seize the mutant child. The Marauders fight in the final battle on Muir Island and Scrambler and Vertigo seemingly all die. The Marauders appeared once again in the ongoing series of X-Force, where a contingent of Marauders clones had recently awakened after the death of Mister Sinister. The team returns to the facility where Vanisher lost the virus and battle the cloned assassins.
Exodus, Frenzy, Gambit, Lady Mastermind, Mystique, Omega Sentinel (possessed by Malice), Polaris (possessed by Malice), Sabretooth, Sunfire, Tempo, [[Threnody]), Hans, Scrambler, Scalphunter, Riptide, Malice, Mr. Sinister, Random, Uncuncione
- Responsible for the murders of hundreds of Morlocks including Tommy, Annalee and Piper.
- Gambit's role in assembling the Marauders and Mister Sinister's reason for attacking them were retroactively added to the original massacre.
- The third Weapon X series reveals that both Scalphunter and Sabretooth joined Sinister decades before the massacre. Scalphunter met Essex during World War II while Sabretooth was approached by Greycrow during the Vietnam War, when Creed worked as a mercenary.