The Infector is a variety of Necromorph from the Dead Space franchise. It appears as a grotesque manta-shaped creature and is responsible for spreading the Necromorph contagion.
Created from a human torso and legs, its wings are formed by a flap of skin from the chest and then fused between the former host's bent and broken legs. The jaw collapses within the body and the rest of the head breaks and twists into its proboscis and feelers and with the spine providing support and attachment points for articulation (movement). The proboscis, made from mutated bone, muscle, and spinal tissue is the delivery mechanism used to infect potential hosts. This is done by enveloping the host in its wings, extending the proboscis from the spinal cavity, and then stabbing it into the skull to inject a yellow fluid stored in an internal bladder.
Infectors will crawl or glide from place to place, seeking new corpses to convert into Necromorphs. In each of the Dead Space games, Isaac Clarke encounters Infectors in areas littered with bodies and must act quickly to kill any Infectors present before they can convert any of the bodies. Failure to kill an Infector promptly will mean having to expend more ammo fighting the new Necromorphs that the Infector creates. Alternatively, Isaac can dismember the bodies in a room so that the Infector will be unable to transform them and focus its attention on Isaac himself.