The Lurker is a type of Necromorph that appears in the Dead Space games and other media. Throughout the games, the creatures known as Lurkers are produced when cloned human infants are infected with the Necromorph pathogen, making it one of the most disturbing varieties of Necromorph known to exist.
Upon infection, the infantile subject's muscle tissue (what little there is) is repurposed into a series of tentacles that emerge from the torso. These tentacles are used for locomotion and the subject's original limbs become rigid and useless for any purpose other than to serve as protection from incoming attacks. The sticky tendrils allow the Lurker to creep along floors and also walls and ceilings.
Most notably, the infectee's back rips open and three tentacles emerge from the cavity. Each tentacle ends in a sharp bone tip which can be fired like bullets from a gun, moving at a high-enough velocity to punch through armour. These appendages make the Lurker a significant threat from a distance or at close range.
Though most commonly formed from repurposed infant bodies, there have been occasions where Lurkers have been created from adult bodies as well. In Dead Space 3, Lurkers aren't created from human corpses at all, but from dogs.