A technician previously employed to create Big Daddies, now fighting to escape Rapture.
Though resourceful and driven to escape the sinking Rapture, Malcolm is not a hero. He doesn't like being shot at, doesn't like killing people, and isn't particularly brave. If the ancient legends of Eternal Heroes are true, then Malcolm is probably the counterpoint, the Eternal Coward. He would rather run for cover than fight, but when backed into a corner, he fights like a trapped rat, scrabbling desperately for anything to save his skin.
Malcolm currently carries a shotgun and an Adam Extraction needle stolen from the Little Sister's Orphanage near where he worked. He has a machine gun turret strapped to a hand cart, and though it is too heavy to really be practical, he's managed to drag it along with him. He has a few proximity mines, but no launcher, so he has to place them by hand. Given his extensive tool kit, he can rig up other weapons, given enough time and resources.
Malcolm used to work for Failsafe Armored Escorts. When he proved to be a better scientist than guard, he was offered a new job working to create Big Daddies. More of a hardware genius than a genetics expert, his job was in Suit Assembly, and he excelled there. His team was responsible for the Rosie design, and he was directly responsible for creating the "Friend or Foe" triggering mechanism for the proximity mines.