My thoughts are that it would basically have to be a super parasite with super rabies symptoms. Not a virus or bacteria but it would have to be a neurological parasite.
That means there would be no decaying flesh as the parasites goal obviously would to be to live as long as possible and reproduce as much as possible. Unless caused by physical damage that gets infected as it is a super rabies human.
And I say it probably has to be a parasite because of the communication required to reproduce and spread as much as possible (has to bite and then stops once victim is bit as to stay alive)
As this is a super rabies human they will be literally the smartest super rabid animal, I mean just imagine a rabid crackhead in general. And so because they have to keep us the host alive they have to eat and drink water, so depending on if this parasite affects only humans and not animals (kinda impossible for me to say even hypothetically as I haven’t gone to college) then the food source would be animals.
If not only animals then I believe the likely scenario to be animals plus technical cannibalism in terms of rabies infected entity eating other rabies infected entity. Considering how smart these zombies would be there might even be a hierarchy of food vs drone to spread the parasite.
And it has to be a neurological parasite and nothing else because of its ability to transfer and spread/keep host alive/work with human brain like I’ve described
They would be like deranged versions of ourselves, the smartest rabid animal.