The simple answer is 'five'... but it goes a bit deeper than that. Let's pick apart each of the main 'classes,' to help you find the droids you're looking for. There'll be a few minor spoilers for ...
Droids may be second-class citizens in the Star Wars universe, but they’re also some of the most important characters in the entire franchise. There’s hardly a hero in the lore of Star Wars ...
Early concept art of the Neimoidians shows them as having very thin faces, and it's easy to see how the B1 series Battle Droids are meant to look like the skeletons of these spindly aliens.
We welcome our Droid-overlords with the arrival of the new Aqua Droids in Star Wars: Legion from Atomic Mass Games!