Monday’s Mutant is Marrow!
Marrow (Sarah) is one of those mutants whose mutation manifests itself in such a way that it cannot be hidden from the outside world. As a child, she was taken in by the Morlocks and lived in the underground tunnels beneath New York City with them, away from the rest of the world. It was here that she came to the attention of the X-Men.
Raised by Morlock Leader Callisto, Marrow leads a violent cell called the Gene Nation and was a mutant terrorist. As she grew older she learned that her actions were wrong and eventually joined the X-Men to redeem herself. She learned to control herself and developed a moral code, yet still fell in with a paramilitary group calling itself Weapon X. Marrow’s tendency to react violently has not always followed in line with the beliefs of the X-Men, she is a trained fighter and assassin whose loyalties are often called into question. A mutant loose cannon with an endless supply of weaponry at her disposal.
Despite her anger and disdain for humanity, Marrow struggles to find peace for herself and desires to co-exist. She has proven herself to be the ultimate team player who is willing to risk her life to save her teammates.
Marrow’s mutation is that her bones grow outside of her skin and can be removed to use as weapons, like knives or clubs. It also provides a shell at times, providing her with body armor to protect her from attack. She also has a healing factor and enhanced immune system much like the Wolverine does. To keep up with her rapid bone growth she has two hearts as well. One of which was ripped out by Storm. It is assumed that with her healing factor, she grew the heart back.
Marrow lost her powers during M-Day and now lives as a woman named Rem, with the visible remains of her lost mutation, a deformity now.
Marrow first appeared in Cable #15, September of 1994, as a child and was created by Joseph Loeb and artist David Brewer.