For those who don't know, those are images used in a mod for minecraft where you can talk to the mobs, and if I am not wrong, there is some eroge mod as well, but I didn't bother into looking for it. Here is the link:
Yes, and it's because while the zombie looks female, it is actually a guy, and according to the default script that comes with the mod, he gets comically depressed if you mistake him for a girl.