Manslaughter is a fictional character appearing in American comic books published by Marvel Comics.

Manslaughter is a mutant or mutate supervillain, a killer and assassin by trade and a psychopath by nature. He was assigned by a drug czar to assassinate the Defenders. He invaded their Rocky Mountain headquarters, and stalked and nearly killed them.^[2] He was turned over to the police in Elijah, Colorado.^[3]

He invaded Defenders headquarters again, and stalked and trapped the Defenders to convince them to let him join their ranks as an adventurer. He was subdued by the Interloper.^[4] Manslaughter aided the Defenders and the Interloper in battle against Moondragon and the Dragon of the Moon. He joined his life force with Andromeda, the Valkyrie, and Interloper to drive the Dragon of the Moon from Earth, and his body turned to dust.^[5]

With the others, they later took on host bodies of living persons, and assisted Doctor Strange in battling and crushing the Dragon of the Moon.^[6]

He later joined the Assassin Nation and fought Cage.^{[volume & issue needed]}

Manslaughter has minor psionic talents, notably limited telepathic powers enabling him to perceive the activity of the autonomic nervous systems of other people. He can use this to influence the peripheral vision and subliminal hearing of others, making him invisible and virtually inaudible from a person's peripheral senses, completely preventing him from being noticed him as long as he stays out of direct sight and moves stealthily.

As his name implies, Manslaughter's obsession is murder, which he views as both art and science. He enjoys studying his targets so that he can devise exotic, tailor-made methods of execution. Using his psionic abilities he can safely stalk his prey while remaining within a very close proximity (even a few feet), and reveals his presence once it is too late for his victims to escape.

Manslaughter has extensive training and experience in all forms of hand-to-hand combat. He has mastery of assorted weaponry, and is an expert marksman and trapper. He was tutored by the Interloper in various mental disciplines and martial arts.

Manslaughter is psychotic and thus highly emotionally unstable.

Manslaughter carries various throwing weapons carried in his shoulder bag such as knives, sais, and shurikens.

• Manslaughter at The Appendix to the Handbook of the Marvel Universe