Parasymbiote

Description from original post (created 2012-08-22 21:12):

The offspring of death and destruction and much worse than both, this creature is a nightmare to humanity in its darkest dreams. The symbiote, an alien parasitic virus that came to the world trapped in a meteor was found by a group of elite scientists that experimented on it. The result was the parasymbiote, an organic machine made by the merge of an past failed experiment for immortality called the parasite droid, and the symbiote. The parasite's lust for a host to suck the energy out of made the merge easier as that is the symbiote's only desire. The parasymbiote was mass produced to stop the war from the attacking mobs, but was soon to powerful to control. The mobs were destroyed but the parasymbiotes couldn't control their need for a host. They were all burned to death and killed off, but the will to live caused a single cell with all the DNA to survive and start them again. They aren't as plentiful as before but when they're there, hiding where you least expect them ready to find a new host, maybe you.

They attack by latching on to the host with the four mechanical arms on their chest and proceed to suck the life and soul out of the host through the hole in their chest where lost souls are kept to fuel the beast. The host is reduced to only a hollow shell. They are part mechanical, part organic, and the ooze on their bodies mostly covers the metal insect legs that act as bones. The result is an impenetrable exoskeleton and near immortality, the only possible way of eradication is fire.