What kind of snake that is all black with tan wide rings and will spread it's neck like a cobra?

There are few species of false cobras, from the markings you described I would say you are thinking of the false water cobra. Image search that and I bet it is the one. They are mildly venomous, rear fanged, and not consider dangerous. If you are thinking about keeping one make sure you research them first. I have worked with them but I am also an experienced snake guy.