Does someone know why some infested units have tentacles growing out of them and are deformed etc (eg. Infested Marine) whilst others, for example that Protoss Matriarch, Stukov etc. still look exactly the same and show no signs of being infested? Thanks!
Any host to Zerg infestation generally need some psionic gift to give the infestation some sort of order, otherwise it runs rampant through the host body, creating random series of mutations which usually drive the host insane and severely limits his/her/its life span. Since most Terrans don't have any psionic abilities, they tend to look very malformed, and die soon after infestation. As for Raszagal, she wasn't infested; she was mind-controlled by Kerrigan. She thought she could resist, but couldn't. Lastly: Looks pretty infested to me. It's also worth noting that Stukov was dead upon infestation, which may yield different results than that of a living host. Or perhaps infestation yields better results when more "effort" is put into it. Look at Kerrigan - she had to be encased in a chrysalis and watched over for some time before she hatched. Maybe Stukov's infestation was supervised in a similar way, that it might yield less deformities.
Thanks for the useful info Kaaraa, I suppose it's impossible to be infested without some sign of changes in appeareance. I tried getting some info on mind controlling Raszagal, but the only thing I could find was 'Kerrigan was powerful enough to gain control of approximately half of the Zerg Swarm and seize the mind of Raszagal without even setting foot on the same planet'. I still find it odd that such an 'advanced' (biologically speaking) race as the Zerg can't infest humans / aliens without changing their appeareance though.
It is because they only have the power to evolve stuff. The zerg larvae carry the genes of all species infested by the swarm, and they use this to change other creatures into zerg as well. Only it is hard to turn a human into a slave by giving him more human DNA, so other stuff is needed.
It's like in the John Carpenter's The Thing movie. The infested humans who were just imitations of some crew members had a normal form of body. It was for the intrigue of the movie. Same thing here in Starcraft : they look like humans not to give any doubt on them. For the storyline.
But Kerrigan was still slightly mutated, what with her 'wings' and all. Is it just that there is no way to not bear a difference in appearance once infested?
That's what I would also like to know Gandromidar, it seems that the answer is no, you can not keep your old appeareance once infested.