Goo Lite

WE have seen and discussed black goo and it's role in xeno development. It makes me wonder if there was any 'lite' goo development. THis would also mix with a host but not to the extreme of the xeno. A goo that can take over the host's body without detroying all of it's brain power and history. A 'lite' goo that has a tremendous survivial will but without the outer xeno appearence. Actually a goo infected victim that functions like a human, for example, but under the skin is all xeno. I am not talking zombie like in a non funtioning manner,,,but a new breed of 'lite'xenos that can be human on the outside but goes about it's survival business with precision, skill and determination to take comntrol of an entire planet without destroying all living occupants. So well intregrated in the host's body that might even fool a robot. Now that would be a xeno with all of the evelness that we have seen and conditioned to but not not cause us to run at first sight because of an alien appearence .